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1-OW  BOOK 


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U  .    S  .    A. 

SECOND    EDITION 


A  Treatise 
on  Plows 
and  plowing 


C  A  BACON 


Published  by 
Oliver  Chilled  PlowVorks 

South  Bond,  IncL 


MAIN  LlBRARY-AGRlCULTURc. 


Preface 

'HE  treatment  of  any  farmer's 
soil  is  entirely  within  his  hands. 
Success  is  measured  by  his 
knowledge  and  the  diligence  with  which 
he  applies  those  laws  of  Nature  which  are 
related  to  crop  growing. 

These  laws  are  universal.  A  farmer 
can  apply  them  to  meet  his  own  partic- 
ular need  better  than  acting  upon  the  ad- 
vice anyone  can  give  him,  because  he 
understands  his  soil  conditions.  Other 
people  do  not. 

The  purpose  of  this  book  is  to  set 
forth  these  laws  and  explain  the  causes 
and  effects. 

The  Oliver  Chilled  Plow  Works  has  a 
desire  to  be  of  practical  value  to  farmers. 
Our  long  experience  in  building  plows  and 
kindred  implements  for  use  all  over  the 
world  has  given  us  an  opportunity  to  ob- 
serve a  great  many  facts  in  connection 
with  plows  and  plowing  which  should  be 
common  knowledge  among  farmers. 

OLIVER  CHILLED  PLOW  WORKS. 
469802 


CONTENTS 

Chapter  Page 

I.  Functions  of  the  Plant  Organs 5 

II.  Influence  of  Water 14 

III.  Importance  of  Air  in  the  Soil 27 

IV.  Soil  Temperature 32 

V.  Why  Soils  Must  Be  Handled  Differently  37 

VI.  Depth  of  Plowing 51 

VII.  When  to  Plow 63 

VIII.  Plowing  to  Kill  Insects 72 

IX.  Plowing  to  Kill  Weeds 79 

X.  Plowing  Under  Green  Manure 87 

XI.  Judging  Plowing 92 

XII.  Plow  Bottoms 97 

XIII.  Plow  Bottom  Metals 129 

XIV.  Scouring  Troubles 137 

XV.  Setting  the  Share  on  the  Plow 1 49 

XVI.  Sharpening  Soft  Center  Steel  Shares.  ...  154 

XVII.  Sharpening  Crucible  Steel  Shares 158 

XVIII.  Sharpening  Chilled  Shares 159 

XIX.  The  Rolling  Coulter 160 

The  Jointer 

The    Combined    Rolling    Coulter    and 
Jointer 

XX.  The  Tractor  Plow  Hitch 167 

XXI.  Adjusting  Horse  Plows 183 

XXII.  Middle  Breakers 189 

XXIII.  Disk  Plows..  195 


CHAPTER  I 


Functions  of  the  Plant  Organs 

'  I  "HERE  is  a  vast  difference  between  operating  a  farm 
•*•  and  a  factory.  The  process  of  manufacture  from  the 
receiving  of  the  crude  materials  to  the  finished  product 
is  entirely  in  the  hands  of  the  manufacturer.  That  is, 
he  can  control  every  step  in  any  process  from  start  to 
finish.  It  is  not  so  with  the  farmer.  The  farmer  can 
control  only  the  operation  of  the  machinery.  He  has 
to  have  a  partner  to  enable  him  to  successfully  grow 
crops.  That  partner  is  mother  Earth.  He  has  to 
depend  upon  her  for  everything  except  the  labor,  which 
is  his  part  of  the  contract. 

Obviously  the  farmer  who  succeeds  best  must  under- 
stand Nature.  It  is  a  hopeless  task  to  learn  all  the 
whims  and  caprices  of  Nature,  but  it  is  possible  to  learn 
how  to  treat  mother  Earth  so  that  she  can  use  these 
whims  and  caprices  of  Nature  to  bring  forth  bountifully. 

The  first  step  in  this  process  is  plowing.  Many 
important  historical  events  offer  the  strongest  evidence 
that  from  the  time  man  first  began  to  till  the  soil  he 
discovered  the  necessity  for  stirring  it  in  some  manner 
before  any  kind  of  a  crop  could  be  grown.  Even  the 
greatest  authors  of  antiquity,  medieval  and  modern 
times,  speak  of  plowing.  We  have  Benjamin  Franklin 
in  our  own  colonial  times  who  advised  farmers  "to  plow 
deep  while  sluggards  sleep  and  you  will  have  corn  to  sell 
and  keep."  Pliny  spoke  in  his  treatise  on  agriculture, 


«&!'<<  -THE  OLIVER  PLOW  BOOK 


of  the  importance  of  having  the  ground  properly  pre- 
pared, and  even  in  the  New  Testament,  in  the  book  of 
St.  Luke,  the  parable  of  the  sower  forcibly  illustrates 
that  Christ  was  a  keen  observer  of  the  laws  of  Nature 
as  related  to  crop  growing. 

"A  sower  went  out  to  sow  his  seed;  and  as  he 
sowed  some  fell  by  the  way  side;  and  it  was  trodden 
down,  and  the  fowls  of  the  air  devoured  it. 

And  some  fell  upon  a  rock;  and  as  soon  as  it  was 
sprung  up,  it  withered  away,  because  it  lacked 
moisture. 

And  some  fell  among  thorns;  and  the  thorns 
sprang  up  with  it,  and  choked  it. 

And  other  fell  on  good  ground,  and  sprang  up, 
and  bare  fruit  a  hundredfold." 

This  quality  to  observe  conditions  as  they  are  is  just 
as  fundamental  to  the  business  success  of  any  man  as 
it  is  for  his  religious  welfare.  There  is  not  such  a 
tremendous  amount  of  difference. 

Evidently  farmers  in  Christ's  time  believed  that  it 
was  necessary  to  kill  the  thorns  and  to  conserve  moisture, 
and  they  believed  still  more  that  it  was  necessary  to 
have  the  ground  "good."  This  word  "good"  involves 
a  great  deal.  Our  modern  soil  phycisists  tell  us  that  we 
plow  to  kill  weeds,  conserve  moisture,  and  to  put  the 
ground  in  a  good  condition  of  tilth.  By  tilth  they 
mean  that  the  land  is  in  shape  to  be  cultivated  easily 
and  in  such  condition  as  to  bring  forth  abundantly. 

Before  one  can  put  ground  in  condition  to  meet  plant 
growth  requirements  he  must  have  a  thorough  under- 
standing of  the  habits  and  characteristics  of  plants  he 
desires  to  grow,  the  kind  of  food  that  plants  require  and 


FUNCTIONS  OF  PLANT  ORGANS 


FRUIT 


A  fully  matured  corn 
plant  showing  the  parts 
that  have  to  do  with  the 
growth  of  the  plant. 
Observe  the  short  root 
system  compared  with 
the  network  °f  roots  of 
the  four  hills  of  growing 
corn  illustrated  on  page 
eleven. 


ROOTS 


THE  OLIVER  PLOW  BOOK 


the  soil  conditions  necessary  for  the  manufacture, 
maintenance  and  proper  distribution  of  that  food  to  the 
plants  as  they  need  it. 

Botanists  tell  us  that  every  part  of  the  plant  has 
functions  which  it  performs  for  its  own  development. 
The  functioning  of  the  various  organs  of  the  plant  is 
naturally  very  different  from  that  of  the  animal,  never- 
theless, these  organs  are  just  as  important  to  the  plant 
as  the  digestive  and  breathing  organs  are  to  the  animal. 
The  greatest  of  care  is  exercised  in  feeding  the  stock. 
The  proper  amount  of  food  and  water  is  given  to  the 
animals  at  the  right  time.  In  the  summer  the  green 
pastures  supply  the  great  percentage  of  food  for  cows. 
In  the  winter  they  are  given  foods  which  produce  milk 
and  flesh.  If  horses  are  being  used  in  the  field  they  are 
fed  the  kind  of  food  that  keeps  them  strong  and  healthy. 
The  same  rule  holds  true  of  the  entire  animal  family. 
No  two  types  of  animals  ever  receive  the  same  kind  of 
food  nor  even  the  same  portion;  that  has  to  be  given 
according  to  their  kind.  The  same  feeding  law  holds 
true  of  plants. 

Plant  life  is  different  from  animal  life.  The  animal 
is  either  fed  by  human  hands  or  goes  about  searching 
its  own  food.  The  plant  is  stationary.  It,  therefore, 
must  subsist  upon  the  food  contained  in  the  air  and 
soil  within  reach  of  its  organs. 

All  crop  producing  plants  have  roots,  stems,  leaves, 
and  flowers,  or  the  fruit.  The  farmer  is  concerned  as 
to  the  quality  and  quantity  of  fruit  produced.  The 
quality  and  quantity  of  fruit  are  determined  by  the 
growth  of  the  leaf  and  stem,  and  also  the  plant's  ability 
to  withstand  the  evil  influences  of  wind,  drouth  and 
excessive  rainfall. 


FUNCTIONS  OF  PLANT  ORGANS 


The  seed  of  any  plant  is  supposed  to  contain  enough 
nourishment  for  growth  until  the  roots  are  large  enough 
to  drink  in  their  nourishment  from  the  surrounding  soil, 
and  the  stem  to  break  through  the  top  of  the  ground  to 
breathe  in  the  required  air. 

The  roots  are  the  organs  that  search  out  into  every 
particle  and  recess  of  the  soil  within  reach  for  plant 
food,  and  carry  it  to  the  stem. 

The  most  important  part  of  the  crop  growing  opera- 
tion consists  in  bringing  about  a  soil  condition  whereby 
the  seed  can  germinate  according  to  its  natural  inclina- 
tion and  the  plant  produce  a  root  system  necessary  for 
vigorous  growth  and  flowering. 

The  little  kernels  in  the  wheat  illustration  were 
sprouted  to  show  how  little  and  tender  are  the  roots 
of  germinating  seeds. 


Four  kernels  of  sprouted  wheat.  The  two  outside  ^ernc/s  would 
sustain  the  plant  until  the  roots  and  stems  could  feed  themselves.  The 
two  inside  plants  were  weak  seeds.  The  seeds  are  entirely  consumed, 
and  the  young  plants  are  not  large  enough  to  support  themselves. 


10  THE  OLIVER  PLOW  BOOK 

It  is  important  that  a  seed  bed  be  in  a  well  pulverized, 
compact  condition  for  the  sprouting  of  seeds  and  grow- 
ing of  plants.  The  little  kernels  of  wheat  must  sprout 
and  grow,  but  before  they  can  do  it  the  plant  food  must 
be  in  the  soil  in  available  form  for  the  little  tender 
roots  to  feed  upon.  Observe  the  sprouts  running  up 
and  the  little  roots  going  downward.  One  pinch  of  the 
root  with  the  fingers  would  kill  it,  yet,  it  is  supposed  to 
grow  and  produce  tenfold  times.  There  is  food  enough 
within  the  kernel,  if  it  is  good  seed,  to  nourish  the  grow- 
ing plant  for  a  short  time,  but  after  that  it  must  reach 
out  into  the  soil  to  find  sustenance,  and  if  that  plant 
grows  rapidly  it  must  have  the  food  within  convenient 
reach  just  when  it  needs  it.  This  is  the  great  reason 
why  the  preparation  of  the  seed  bed  is  the  most  im- 
portant part  of  the  crop  growing  operation.  It  matters 
not  how  good  the  seed,  if  the  soil  is  not  in  the  right  con- 
dition to  make  plant  food  available  to  nourish  the 
starting  plant,  growth  will  be  stunted.  Pulverizing  the 
ground  when  plowing  is  the  first  and  most  vital  step  to 
accomplish  this  end 

There  is  another  reason  why  a  compact  seed  bed  is 
necessary.  After  the  seed  has  sprouted,  and  the  plant 
has  acquired  its  growth,  more  food  is  necessary  for  the 
flowering  of  the  grain.  The  roots  are  searching  through 
the  ground  by  means  of  their  continued  growth  to  find 
this  food.  The  better  the  seed  bed  is  pulverized,  the 
more  available  food  the  roots  find.  They  form  a  net- 
work of  food  seekers  entirely  occupying  the  ground  from 
one  plant  to  another. 

The  corn  field  illustration,  in  which  the  rain  has  washed 
away  the  earth  from  the  roots,  shows  the  interweaving 
of  the  root  system  of  corn.  Each  of  the  little  hair 


FUNCTIONS  OF  PLANT  ORGANS  1 1 

roots  drinks  in  its  share  of  food  for  the  plants.  When 
we  consider  that  plants  are  soup  eaters,  that  is,  all  the 
food  the  roots  absorb  is  taken  in  liquid  form,  the  im- 
portance of  having  the  best  possible  seed  bed  from  top 
to  bottom  is  obvious. 


When  the  rain  washed  away  the  earth  it  generously  left  the  corn  roots 
in  much  the  same  position  as  they  would  be  found  if  it  were  possible  to 
look,  into  the  earth. 

A  study  of  this  illustration  shows  how  easy  it  is  to  break  these  roots 
by  cultivation.  Recognizing  that  roots  are  necessary  for  absorbing  (he 
food  contained  in  the  soil,  the  importance  of  protecting  this  root  system 
and  giving  it  every  opportunity  becomes  apparent. 

The  stems  are  the  conveyors  of  this  food  to  the  leaves 
and  the  flowers  and  also  serve  the  important  purpose  of 
holding  up  the  flowers  and  leaves  from  the  ground  to 
give  them  an  opportunity  to  do  their  work. 

The  leaf  has  four  principal  functions  to  perform.  It 
has  to  do  with  the  starch  making  properties  of  the  plant, 


12  THE  OLIVER  PLOW  BOOK 

the  assimilation,  the  excretion  of  water,  and  breathing. 
The  functions  of  the  leaves  in  these  four  processes  in- 
volve a  very  complicated  chemical  process  which  is  not 
very  thoroughly  understood  and  does  not  need  to  be 
from  a  practical  standpoint. 

The  only  thing  necessary  to  know  is  that  a  plant,  to 
flower  and  produce  the  proper  grain,  must  have  an 
abundance  of  moisture  in  order  that  the  sunlight  and 
air  may  supply  the  proper  gases  and  heat  necessary  to 
bring  about  these  chemical  changes.  The  task  of  the 
farmer  is  to  see  that  air,  water  and  the  proper  plant  food 
elements  are  properly  proportioned  in  the  soil.  He  need 
not  worry  about  the  part  that  surface  air  plays  in  the 
growing  of  the  plants  because  it  is  beyond  his  control. 
Nature  always  supplies  it  abundantly  on  and  above  the 
earth's  surface.  To  be  of  the  utmost  value  air  must  be 
permitted  to  permeate  every  particle  of  the  seed  bed. 

The  tiller  of  the  soil  must  see  that  the  proper  amount 
of  plant  food  is  supplied  during  the  plant's  life  so  that 
the  entire  plant  can  perform  its  functions.  He  must 
not  forget  also  that  a  plant,  even  as  any  animal,  can 
gorge  itself  so  that  one  part  of  it  will  grow  to  the  detri- 
ment of  another. 

The  plant  may  be  considered  in  part  as  its  own  food 
manufacturing  establishment;  that  is,  certain  of  the  food 
elements  coming  from  the  soil  are  mingled  with  the 
gases  which  come  through  the  leaves  in  such  a  way  as  to 
form  the  starchy  substances  of  the  plants.  It  is  vitally 
necessary,  therefore,  that  both  the  soil  and  air  supply 
the  proper  elements  for  these  processes  to  take  place  in 
the  plant. 

The  amount  of  plant  food  contained  in  water  is  very 
small,  hence,  the  plant  must  consume  an  immense 


FUNCTIONS  OF  PLANT  ORGANS  13 

amount  of  water  to  derive  the  sustenance  necessary.  A 
grass  plant  has  been  found  to  give  off  its  own  weight  in 
water  every  twenty-four  hours  in  hot,  dry  summer 
weather.  This  would  make  about  6J/2  tons  of  water  per 
acre  for  every  twenty-four  hours  in  ordinary  grain  fields. 
This  proves  that  moisture  is  one  of  the  most  essential 
items  for  producing  plant  growth  and  must  be  properly 
provided. 

Botanists  maintain  that  95  to  97  per  cent,  of  all  the 
materials  from  which  Nature  builds  the  tissues  of  her 
plants  are  taken  from  the  air.  It  is  important,  then, 
that  we  know  by  what  process  the  materials  from  the 
air  are  transformed  into  plant  food,  particularly  that 
part  of  the  process  which  Nature  depends  upon  tillage 
and  the  soil  to  perform. 

Nature  furnishes  the  moisture,  air,  light  and  soil. 
She  expects  us  to  till  the  soil  in  order  that  she  may  use 
the  moisture,  air,  light  and  soil  to  the  best  advantage  in 
transforming  materials  into  plant  food  for  growing 
crops.  She  rewards  bountifully  those  who  work  with 
her,  and  she  recompenses  poorly  those  who  do  not. 

Working  with  Nature  means  a  knowledge  of  the  effect 
of  moisture,  air,  light  and  heat  upon  the  soil  and  apply- 
ing that  knowledge  in  a  practical  manner. 


CHAPTER  II 


Influence  of  Water 

WATER  is  the  greatest  single  factor  in  plant  growth. 
It  seldom  rains  at  just  exactly  the  right  time  for  its 
use.  The  task  is  to  keep  this  moisture  where  it  can  be  uti- 
lized by  the  growing  plants  just  as  rapidly  as  they  need 
it.  Before  this  can  be  done  successfully  one  must  have  a 
knowledge  of  the  characteristics  of  the  different  types 
of  soils,  their  capacity  for  holding  moisture  and  the 
rapidity  with  which  it  percolates  and  evaporates,  also 
the  things  that  are  necessary  to  permit  moisture  to  sink 
into  the  ground  and  keep  it  from  escaping. 

Water  is  the  solvent  of  mineral  elements  in  the  soil 
which  nourish  the  plant,  and  since  plants  can  absorb 
mineral  salts  only  in  solution,  water  is  absolutely  nec- 
essary to  enable  the  plant  to  take  nourishment  from  the 
soil. 

Water  is  the  means  whereby  plant  food  elements  are 
transformed  into  plant  food  because  without  it  there 
can  be  no  chemical  action  or  reaction  to  transform  the 
elements  into  plant  food.  Water  also  holds  in  solution 
food  for  the  plant,  carries  it  from  the  hair  roots  to  the 
stem,  and  from  the  stem  to  the  places  where  growth  is 
taking  place,  transports  plant  food  from  one  place  to 
another  in  the  soil,  and  is  a  temperature  regulator  for 
the  soil. 

From  75%  to  90%  of  the  fresh  substance  in  crops  is 
water,  thus  water  in  itself  is  plant  food  and  essential  to 


INFLUENCE  OF  WATER  15 

plant  life.     The  greater  part  of  this  per  cent,  enters  the 
plants  through  the  roots. 

The  75%  to  90%  of  water  making  the  fresh  substance 
of  plants  is  water  in  plant  composition,  and  can  only  be 
taken  from  the  plants  by  excessive  heat.  However, 
this  water  in  composition  is  dependent  upon  the 
amount  of  moisture  contained  in  the  soil  and  the  humid- 
ity of  the  atmosphere  because  the  growth  of  the  plant  is 
retarded  or  advanced  as  the  amount  of  moisture  in  the 
soil  is  available.  This  moisture  in  turn  is  controlled 
more  by  the  soil  than  the  atmospheric  temperature. 
Hence,  it  is  necessary  to  have  moisture  in  the  ground  in 
the  right  proportion  for  regulating  the  heat  to  retard  the 
process  of  evaporation  as  well  as  to  promote  the  develop- 
ment of  plant  food. 

It  is  impossible  to  definitely  define  what  amount  of 
moisture  is  required  for  the  growth  of  a  plant  because  a 
great  many  conditions  enter.  A  crop  may  require  300 
tons  of  water  for  growth  to  maturity.  It  may  be  nec- 
essary for  the  soil  to  furnish  350  tons  on  account  of 
varying  conditions.  Some  the  farmer  can  control, 
others  he  cannot.  Water  that  must  be  supplied  for  the 
growing  crops  includes  that  which  is  constantly  evapor- 
ating from  the  ground  and  also  that  which  the  leaf  and 
stem  of  the  plant  are  giving  off. 

The  amount  of  plant  food  in  water  is  very  small;  that 
is,  the  solution  is  in  a  very  diluted  form.  For  this 
reason  a  plant  consumes  many  times  its  weight  in  water 
to  get  the  necessary  food. 

The  principal  factor  which  determines  the  water 
requirements  of  a  plant  is  the  humidity  of  the  atmos- 
phere. In  climates  where  the  atmosphere  is  moist  the 
water  requirements  for  the  plants  are  much  less  than 


16  THE  OLIVER  PLOW  BOOK 

those  in  dry  climates.  The  reason  for  this  is  the  amount 
of  evaporation  from  the  leaves  and  stems.  The  more 
humid  the  atmosphere  the  less  moisture  it  takes  from 
the  plants,  the  dryer  the  atmosphere  the  more  moisture 
it  draws  from  the  plants.  If  the  atmosphere  were 
thoroughly  saturated  at  all  times  the  water  require- 
ments for  the  plants  would  be  very  small  because  of  the 
light  transpiration  of  water  from  the  soil. 

Another  peculiar  fact  in  connection  with  the  water 
required  is  shade.  Shade  increases  the  amount  of 
water  required  for  plant  growth.  It  retards  the 
process  by  which  the  plant  constructs  its  tissues  because 
the  rays  of  sunlight  necessary  for  this  process  are  dimin- 
ished. 

Soil  fertility  has  a  great  deal  to  do  with  the  amount 
of  moisture  required  to  grow  a  crop.  A  poor  soil  requires 
more  water  than  a  rich  soil  for  the  simple  reason  that 
the  more  fertility  there  is  in  the  soil  the  stronger  the 
water  holding  content.  A  soil  may  be  fertile  in  all  the 
elements  but  one.  The  lack  of  this  one  causes  the  soil 
to  require  more  moisture  because  growth  is  retarded 
when  a  plant  fails  to  get  any  one  of  the  elements  neces- 
sary. The  plant  keeps  on  using  and  giving  off  water 
exactly  the  same  as  though  all  the  elements  were  in  the 
soil. 

The  great  problem  is  to  catch  and  save  as  much  of  the 
rainfall  as  pdssible.  The  ground  below  the  seed  bed 
must  act  as  a  reservoir  to  hold  enough  water  for  it  to 
come  upward  by  capillary  attraction  to  the  root  bed 
and  not  escape  into  the  air. 

Capillary  water  is  that  which  adheres  or  clings  to  the 
surface  of  the  soil  grains  and  to  the  roots  of  plants  in 
films  thick  enough  to  allow  surface  tension  to  move  it 


INFLUENCE  OF  WATER  17 

from  place  to  place.  It  is  Nature's  means  of  keeping  a 
constant  supply  where  plants  can  use  it.  Capillary  water 
is  the  chief  source  from  which  plants  derive  their  supply. 
So  important  is  capillary  water  that  crops  grown  on 
moderately  fertile  plots  where  water  was  supplied  as 
fast  as  plants  could  utilize  it,  produced  more  than  four 
times  as  much  as  the  same  crop  grown  in  an  adjacent 
field  under  ordinary  conditions.  The  reason  for  this  is 
simply  that  during  all  the  growing  period  rains  do  not 
come  at  the  right  times.  This  naturally  prevents  the 
plant  food  from  becoming  available  every  day  as  the 
growing  plants  demand.  It  is  like  stuffing  a  boy  one 
day  and  expecting  him  not  to  get  hungry  for  a  week. 
Feed  the  boy  what  he  needs  each  day,  and  he  grows  into 
a  strong  man.  So  it  is  with  plants. 


B 


The  picture  (A)  of  the  tube  filled  with  fine  soil  particles 
with  the  clods  in  the  center  illustrates  very  common 
conditions  in  plowed  ground.  The  clods  in  the  center 
prevent  capillarity  between  the  upper  and  lower  portion 
of  finely  pulverized  soil.  Consequently,  the  moisture 


18 


THE  OLIVER  PLOW  BOOK 


from  below  cannot  reach  the  pulverized  soil  above  the 
clods  any  faster  than  the  rays  of  light  and  heat  evaporate 
from  above.  This  is  plainly  noticeable  in  the  views 
showing  the  water  at  different  heights  in  the  tubes. 

In  illustration  B  observe  that  the  water  has  traveled 
upward  in  the  tube  to  a  level  much  higher  than  the 
water  in  the  pan,  showing  the  force  of  capillary  action. 
Also  observe  the  firmly  compact  condition  of  the  earth 
as  far  as  the  water  has  traveled. 


This  is  the  way  plowing  is  generally  done.  The  large  air  spaces  at 
the  bottom  of  the  first  furrow  slice  and  the  smaller  one  in  the  bottom  of 
the  third  are  often  found  in  fields  that  have  been  harrowed  and  are  sup- 
posed to  be  ready  for  planting.  These  air  spaces  interfere  with  the 
upward  trend  of  capillarity  just  exactly  as  is  shown  in  the  tubes  on  page 
seventeen. 

The  sectional  view  of  plowed  ground  in  the  illustration 
above  shows  very  much  the  same  condition  as  shown 
in  the  tube. 


INFLUENCE  OF  WATER  19 

In  illustration  C  the  water  has  reached  the  bottom  of 
the  cloddy  portion.  The  uneven  edge  shows  that  where 
the  soil  particles  are  compact  the  water  climbs  upward, 
thus  illustrating  an  important  characteristic  of  capil- 
larity. Too  many  air  spaces  in  the  cloddy  ground 
break  up  the  capillarity  so  that  water  will  not  climb  as 
rapidly  or  as  effectively  and  abundantly  as  it  does  in 
soil  finely  compacted.  Two  hours  were  required  for 
the  water  to  rise  from  the  bottom  of  the  tube  to  the 
cloddy  portion. 

Illustration  D  is  the  same  tube  photographed  22  hours 
later.  Observe  that  the  soil  is  thoroughly  permeated 
with  water  up  to  the  cloddy  portion,  that  the  moisture 
in  the  cloddy  part  and  the  pulverized  part  above  the 
clods  is  very  slight,  and  that  on  top  no  moisture  is  to  be 
discerned.  This  shows  that  moisture  does  not  rise  to 
the  surface  of  the  ground  any  faster  than  it  is  evaporated. 
If  this  tube  contained  a  plant  above  the  cloddy  part  it 
would  be  plainly  evident  that  the  amount  of  moisture 
the  roots  could  secure  would  not  be  enough  to  promote 
the  healthy  growth  of  the  plant.  Therefore,  it  is  very 
important  that  this  cloddy  condition  does  not  exist  at 
the  bottom  of  the  seed  bed  as  much  on  account  of 
moisture  as  heat  and  air. 

Film  water  displays  itself  only  upon  the  surface  of  the 
soil  grain.  That  is  why  it  is  called  film  water.  It 
forms  a  film  around  the  grain.  Anyone  can  easily 
satisfy  himself  as  to  the  truth  of  this,  by  taking  a 
marble  and  immersing  it  in  a  glass  of  water,  then  with- 
drawing it.  All  the  water  required  to  form  the  film  will 
cling  to  the  marble  and  the  rest  will  drop  off.  Suppose 
that  marble  is  one  inch  in  diameter.  It  will  fill  a  cube 
one  inch  square — that  is,  six  points  on  the  surface  of  the 


20  THE  OLIVER  PLOW  BOOK 

marble  will  touch  six  points  of  the  cube  and  all  the  rest 
of  the  space  between  the  cube  and  the  surface  of  the 
marble  is  air  space.  The  area  of  the  surface  of  the 
marble  is  found  by  multiplying  the  diameter  squared  by 
3.1416,  making  3.1416  square  inches  of  film  surface  for 
the  water.  This  is  the  amount  of  the  film  surface  dis- 
played. 

A  cube  one  inch  square  will  hold  1 ,000  marbles  one- 
tenth  of  an  inch  in  diameter.  The  square  inch  of  surface 
of  each  marble  one-tenth  of  an  inch  in  diameter  is  one 
hundredth  of  what  it  is  on  the  large  marble,  or  .031416 
of  an  inch.  This  multiplied  by  1 ,000,  the  number  of 
marbles  of  this  diameter  required  to  fill  the  cube,  makes 
31.416  square  inches  of  film  surface,  in  contrast  with  the 
3.1416  displayed  in  the  one  marble.  Thus,  if  you  take 
the  1 ,000  marbles  in  the  cube  immersing  them  in  water, 
and  withdrawing  them  as  you  would  the  large  marble, 
you  would  have  31.4+  square  inches  of  surface  holding 
water,  against  3.1+  square  inches  on  the  large  marble. 
This  means  that  the  air  spaces  have  been  diminished  in 
size  and  the  water  holding  content  of  the  soil  increased, 
proving  that  the  finer  the  soil  is  broken  up,  the  greater 
water-holding  capacity  it  has,  consequently,  the  break- 
ing of  the  soil  into  fine  particles  is  necessary  to  improve 
it  for  water  holding  content.  For  this  reason  the 
ground  should  be  well  pulverized  when  plowing. 

It  is  further  evident,  from  the  marble  illustration,  that 
the  size  of  the  soil  particles  has  everything  to  do  with 
the  water  holding  content.  As  an  illustration  of  the 
capacities  of  different  soils,  for  capillary  attraction  and 
for  holding  water,  samples  of  clay,  clay  loam,  loam, 
sandy  loam,  and  loamy  sand  were  placed  in  the  tubes 
under  the  names,  small  clods  being  placed  on  top  of  the 


INFLUENCE  OF  WATER 


21 


Dipping  a  marble  into  a 
glass  of  water  as  shown  in 
this  illustration  will  con- 
vince anyone  that  surplus 
water  will  not  cling  to  the 
marble  when  it  is  removed. 
Enough  water  should  be 
supplied  in  the  soil  so  that 
a  film  of  water  surrounds 
the  soil  grains. 


7  he  six  points  of  contact 
leave  large  air  spaces  which 
retard  capillary  attraction 
and  permit  an  excessive 
amount  of  air  and  heat  to 
evaporate  what  little  moist- 
ure may  be  in  cloddy 
ground. 


The  thousand  marbles 
make  six  thousand  points 
of  contact  thus  showing  how 
much  easier  it  is  for  moist- 
ure to  travel  upward  by 
capillarity,  the  increased 
surface  for  holding  film 
Water  and  diminished  air 
spaces. 


22  THE  OLIVER  PLOW  BOOK 

finely  pulverized  soil.  Clay  has  the  smallest  soil  particles ; 
clay  loam  the  next  larger,  loam  larger  than  clay  loam; 
sandy  loam  larger  than  loam;  and  loamy  sand  larger  than 
sandy  loam.  This  pan  was  filled  with  water,  giving  it 
an  opportunity  to  rise  in  the  tubes  by  capillarity. 


The  five  samples  of  soil  in  these  tubes  were  taken  from  the  same  farm. 
They  are  shown  on  pages  39,  41,  43,  45  and  47.  At  the  top  of  each  tube 
is  a  granular  mulch.  The  particles  of  earth  are  much  coarser  than  those 
of  the  finely  compacted  earth  below.  These  tubes  are  eight  inches  high 
and  two  inches  in  diameter.  The  earth  was  packed  in  each  tube  to  bring 
about  an  ideal  condition  for  capillary  attraction  to  act.  The  soil  was 
also  placed  in  an  ideal  condition  for  germination  of  the  seed  and  the 
growth  of  the  plant.  The  surface  was  not.  Do  not  fail  to  observe  the 
effect  of  this  granular  mulch  in  the  illustration  on  page  twenty-four. 

The  illustration  at  the  top  of  page  twenty-three 
shows  the  water  is  almost  halfway  to  the  top  of 
the  finely  pulverized  earth  in  the  tube  of  the  loamy 
sand;  has  a  good  start  in  the  sandy  loam;  is  just 
beginning  in  the  loam;  is  hardly  perceptible  in  the  clay 
loam,  and  not  at  all  in  the  clay.  Thus,  we  observe  that 
up  to  this  period  capillary  attraction  is  faster  in  the 
sandy  soils  than  the  clay,  and  that  the  loam  is  about 
midway  between. 

The  second  illustration  on  page  twenty-three  shows 
the  water  in  the  tube  filled  with  clay  has  just  started 


INFLUENCE  OF  WATER 


23 


while  that  in  the  loamy  sand  tube  has  almost  reached 
the  top.  The  clay  loam,  loam,  and  sandy  loam  are  still 
drawing  water  in  about  the  same  proportion  as  shown 
in  the  previous  illustration. 

The  illustration  on  page  twenty-four  shows  the 
water  in  the  tube  filled  with  loamy  sand  has  reached 
the  cloddy  portion,  while  that  in  the  clay  tube 
has  gone  about  one-fifth  of  the  way  to  the  top  of  the 
tube.  The  water  in  the  other  three  is  still  climbing  in 
the  same  proportion,  thus  showing  conclusively  that  the 
finer  the  soil  particles  are,  the  slower  the  water  rises. 


24 


THE  OLIVER  PLOW  BOOK 


Another  feature  that  must  be  taken  into  serious  con- 
sideration is  that  soils,  in  which  water  rises  rapidly,  dry 
out  equally  fast,  thus  the  sandy  soils  dry  out  much 
quicker  than  the  clay  soils,  all  of  which  goes  to  show  that 
the  finer  the  soil  particles  are,  the  stronger  the  attrac- 
tion to  hold  the  water. 


Compare  the  water  in  the  loamy  sand  and  clay  tubes  illustrated  on 
page  twenty-three  with  those  illustrated  above.  The  granular  mulch  on  top 
the  tube  of  loamy  sand  stopped  the  upward  trend  of  moisture  as  the 
distance  the  water  in  the  clay  tube  has  travelled  upward  shows.  The 
moisture  in  the  loamy  sand  tube  has  climbed  from  a  point  just  below  the 
wire  to  the  granular  mulch  while  the  water  in  the  clay  tube  travelled 
twice  as  far  as  it  had,  thus  showing  that  the  granular  mulch  stopped  the 
upward  trend  of  moisture.  This  illustration  serves  to  show  the  import- 
ance of  keeping  the  soil  particles  on  the  surface  in  an  entirely  different 
arrangement  from  those  below  in  order  that  capillary  attraction  may  be 
permitted  to  act  up  to  this  point  and  then  stopped,  thus  peeping  the 
moisture  in  the  ground. 

Observe  further  the  soil  at  the  top  of  the  tube  filled 
with  loamy  sand;  that  the  water  has  not  penetrated  the 
clods  to  any  appreciable  extent.  Bearing  in  mind  the 
illustration  of  the  tube  with  the  clods  in  the  center,  it 
will  be  observed  that  a  granular  surface  on  top  is  better 
to  prevent  moisture  from  escaping  into  the  air  than  the 
finely  pulverized  soil.  The  reason  for  this  is  simply 
that  capillarity  has  been  broken  up  between  the  com- 


INFLUENCE  OF  WATER  25 

pact  sub-surface  and  the  granulated  top.  For  this  reason 
it  is  better  to  have  the  lower  portion  of  the  soil  compact 
and  the  layer  on  the  surface  coarse  and  granular  than  to 
have  it  all  finely  pulverized. 

When  a  farmer  desires  to  plant  a  field  infested  with 
cutworms,  grubworms,  wireworms,  or  some  other  pest 
which  can  be  eradicated  by  plowing,  he  wants  to  know 
whether  it  is  best  to  plow  for  the  express  purpose  of  kill- 
ing the  insects,  for  the  conservation  of  moisture,  or  at  a 
time  of  the  year  when  plowing  can  be  easier  done.  He 
must  decide  which  is  the  most  important  and  plow  ac- 
cordingly. The  number  of  times  that  one  would  run 
into  difficulty  with  moisture  when  plowing  to  kill  insect 
pests  would  be  very  few  because  the  ideal  time  to  plow 
to  kill  insect  pests  is  during  their  larva  state,  which  for 
the  most  part  is  in  the  fall  of  the  year. 

If  one  plans  on  plowing  sod  with  the  expectation  of 
growing  a  crop  it  is  better  to  fall  plow  for  the  moisture 
conservation  process  and  also  for  the  killing  of  insect 
pests.  The  small  profit  that  may  be  made  in  pasturing 
such  fields  is  much  less  than  the  total  accruing  from 
plowing  in  the  fall  previous  to  planting.  This  has  been  dem- 
onstrated sufficiently  to  be  stated  as  a  fundamental  fact. 

If  one  studies  carefully  the  conditions  mentioned  it  is 
evident  that  the  damage  done  during  dry  periods  can 
be  minimized  by  having  the  soil  kept  in  the  proper 
physical  condition  by  the  right  kind  of  tillage  to  save 
moisture  for  use  at  this  time. 

From  the  foregoing  it  is  obvious  that  soil  moisture 
very  often  determines  whether  a  yield  will  be  large  or 
small.  The  same  needs  for  moisture  are  present, 
north,  east,  south  and  west,  and  the  same  laws  for  con- 


26  THE  OLIVER  PLOW  BOOK 

serving  must  be  applied.  The  degree  to  which  this 
conservation  must  be  practiced  is  determined  solely  by 
the  amount  of  moisture  contained  in  the  soil.  In  the 
more  humid  districts  it  may  be  only  necessary  to  adopt 
a  system  for  conserving  the  rains  of  summer  and  fall; 
whereas,  in  the  dryer  territories  it  may  be  necessary  to 
practice  a  system  of  summer  fallowing  for  an  entire  year 
before  enough  moisture  can  be  saved  to  insure  a  crop. 
The  big  thing  to  remember  is  that  moisture  must  be 
present  when  the  plants  need  it. 

Those  farms  underlaid  with  clay  soils  are  easier  to  till 
for  conserving  moisture  for  future  use  than  those  which 
have  an  endless  depth  of  sand  or  gravel.  If  the  sub-soil 
is  of  such  a  nature  that  it  will  not  hold  moisture  within 
the  distance  which  capillary  attraction  operates,  the 
problems  are  extremely  difficult  and  almost  beyond 
control  unless  the  soil  is  kept  chock  full  of  humus  at  a 
depth  deep  enough  to  prevent  surface  heat  from  evapor- 
ating the  moisture. 


CHAPTER  III 


Importance  of  Air  in  the  Soil 

WATER,    heat   and    oxygen  are   necessary    for    the 
germination  of  seeds.    Oxygen  must  come  from  the 
air,  hence  it    is    necessary,    in    the  preparation  of   the 
seed  bed,  to  leave  the  ground  in  condition  for  the  cir- 
culation of  air. 

In  view  of  the  fact  that  seeds  must  germinate  before 
the  plants  can  grow,  the  nearer  the  oxygen  and  moisture 
are  in  the  right  proportion  in  the  ground,  the  more 
rapid  will  be  the  germination  and  growth  of  the  plant. 

In  the  development  of  plant  food  for  growing  plants 
the  elements  that  go  to  make  nitrates  are  largely  con- 
fined to  the  first  few  feet  of  surface  soil.  If  the  soil  is 
loose  enough  to  allow  access  of  air,  nitrification  is  more 
rapid,  hence  plant  growth  is  more  rapid.  It  obviously 
follows  then  that  plowing  and  cultivating  are  necessary 
for  the  development  of  plant  food. 

Air  is  also  necessary  to  keep  the  ground  in  condition 
for  the  retention  of  plant  food  after  it  has  reached  the 
nitrate  form.  The  roots  of  plants  need  oxygen  in  the 
process  of  growing.  Energy  is  required.  The  roots 
penetrating  through  the  ground  absorb  the  oxygen  and 
thus  acquire  the  needed  energy  for  the  work  of  pushing 
the  soil  particles  to  one  side. 

Nitrogen,  in  the  form  of  nitric  acid,  is  the  most  im- 
portant of  all  plant  food  elements.  Oxygen  gives  life 
or  activity  to  prevent  destruction  of  nitrates  after  they 
have  once  been  made.  Wet  soils,  rich  in  organic 


28 


THE  OLIVER  PLOW  BOOK 


matter,  often  give  off  more  free  nitrogen  than  is  used  in 
forming  the  nitrates  in  them.  Thus  they  become 
depleted  on  account  of  too  much  water  and  not  enough 
oxygen.  Too  much  oxygen  in  the  soil  burns  up  the 
fertility  and  has  a  tendency  to  form  clods. 

Seeds  will  not  germinate  in  ground  from  which  oxygen 
has  been  completely  excluded;  neither  will  growth  take 
place.  Water,  completely  filling  pore  spaces,  excludes 
oxygen.  This  is  another  way  of  saying  that  plants  drown. 
The  human  being  drowns  because  oxygen  is  excluded 
from  the  lungs;  so  do  plants.  Compact  earth  prevents 


This  illustration  shows  a  soil  that  had  been  covered  with  water  for  a 
long  time.  The  excessive  air  spaces  caused  by  these  cracks  are  due  to 
the  shrinking  of  the  soil  particles  after  the  swelling  caused  by  the  water. 
It  is  easy  to  see  that  the  cracks  penetrate  deeply  thus  causing  the  air  and 
heat  of  the  sun  to  evaporate  the  moisture  from  a  great  depth. 


circulation  of  air  and  creates  a  condition  fatal  to  growth, 
even  if  the  ground  contains  sufficient  moisture.  Some 
authorities  claim  poisonous  gases  are  formed  by  this 
condition. 

While  the  evil  effects  of  excluding  air  from  the  soil 
are  many,  it  is  equally  true  that  too  much  air  is  harmful. 
Air  is  just  as  essential  in  the  forming  of  nitrates  as 


IMPORTANCE  OF  AIR  IN  SOIL  29 

moisture.  Consequently,  if  all  the  air  were  removed 
from  the  ground  there  would  be  no  forming  of  nitrates, 
and  plant  food  could  not  be  produced.  Too  much  air 
makes  cracks  and  fissures  in  the  soil,  drawing  out 
moisture,  oftentimes  to  such  a  depth  as  not  only  to 
stunt  the  crop,  but  kill  it.  Too  much  air  in  the  soil  in 
the  spring  can  easily  cause  the  loss  of  enough  moisture 
to  grow  a  crop. 

It  is  a  well  known  fact  that  the  atmospheric  pressure 
on  the  earth's  surface  is  14.7  pounds  per  square  inch  at 
sea  level.  The  amount  of  nitrogen  in  these  14.7  pounds 
of  pressure  is  77%.  It  is  perfectly  logical,  if  the 
ground  is  broken  up  and  thoroughly  pulverized  when 
plowing,  that  this  pressure  of  14.7  pounds  per  square 
inch  will  force  the  air  into  the  soil  taking  with  it  77%  of 
free  nitrogen.  It  is  the  air  circulating  around  every 
particle  of  soil  in  conjunction  with  capillary  moisture 
that  liberates  plant  food  for  the  growing  plants. 


This  field  is  similar  to  that  shown  on  page  twenty-eight  but  in  a  much 
less  aggravated  form.  However,  if  left  to  itself  for  any  length  of  time  it 
is  easily  possible  to  see  how  the  cracks  would  widen  and  deepen. 


30  THE  OLIVER  PLOW  BOOK 

Scientists  tell  us  that  wheat,  oats,  barley,  rye,  etc., 
take  up  the  nitrogen,  which  they  use  from  the 
roots,  and  then  only  in  nitrates  in  dissolved  form.  Hence, 
nitrogen  must  be  available  in  the  ground. 

The  more  nitrates  there  are  in  the  ground  per  acre 
the  greater  chance  the  farmer  has  of  growing  increased 
crops.  He  may  have  his  phosphorous,  potassium,  cal- 
cium and  water,  but  unless  he  has  the  nitrogen  which 
he  can  get  from  the  free  air,  he  can  never  grow  the  proper 
kind  of  crop. 

Since  the  need  for  air  in  the  soil  is  highly  important  it 
behooves  the  plowman  to  be  very  careful  to  see  that  the 
ground  is  thoroughly  pulverized  and  that  all  large  air 
spaces  are  eliminated  and  the  after  preparation  of  the 
seed  bed  made  so  as  to  keep  the  air  and  moisture  mixed 
in  the  ground  in  as  nearly  the  perfect  proportion  as 
possible.  Enough  has  been  said  to  show  that  the  perfect 
condition  in  all  soils  is  when  the  soil  has  natural  air 
spaces  between  the  soil  particles.  This  is  one  reason 
why  Nature  makes  soil  particles  with  irregular  surfaces. 
The  best  way  for  aerating  the  ground  is  to  thoroughly 
pulverize  when  plowing.  To  be  sure  of  this  requires  a 
study  of  the  shapes  and  sizes  of  plow  bottoms,  because 
different  soils  require  different  shapes,  sizes  and  curva- 
tures of  bottoms  to  bring  about  the  desired  result. 
Also  the  time  of  the  year  that  the  plowing  is  done  with 
relation  to  the  time  elapsing  between  the  plowing  and 
planting  has  a  great  deal  to  do  with  the  success  of 
this  practice. 

In  the  chapter  on  the  temperature  of  the  soil  atten- 
tion is  called  to  the  difference  in  the  temperature  required 
for  the  most  propitious  development  of  plant  food  and 
the  planting  of  wheat  to  resist  the  winter's  freezing. 


IMPORTANCE  OF  AIR  IN  SOIL 


31 


Observe  how  deeply  fissures  will  penetrate  the  ground  when  conditions 
are  ripe.  This  condition  can  only  be  prevented  by  a  mulch  of  earth  on 
the  surface  to  keep  moisture  travelling  upward  from  the  ground  water 
level  to  the  mulch,  and  the  rays  of  heat  and  light  from  penetrating. 

Summing  up  the  importance  of  air  in  the  soil,  temper- 
ature and  plant  food  development,  and  the  killing  of 
insect  pests  we  find  that  early  summer  plowing,  with 
complete  burying  of  stubble  and  trash  on  the  bottom 
of  the  furrow,  is  the  best  method  for  killing  the  Hessian 
fly,  and  aerating  the  soil  at  a  time  when  nitrates  develop 
best.  At  this  time  there  is  the  least  amount  of  rainfall 
to  wash  away  plant  food  and  the  soil  is  in  the  best 
possible  condition  for  the  percolating  and  saving  of 
what  rain  does  fall  so  that  later  in  the  fall  when  the 
time  comes  for  planting  wheat  it  is  at  a  cooler  temper- 
ature with  plant  food  enough  developed  for  giving  the 
wheat  a  remarkably  good  start,  thus  lessening  its 
chances  of  winter  killing. 


CHAPTER  IV 


Soil  Temperature 

FOR  centuries  farmers  have  observed  that  some  soils 
are  seemingly  better  adapted  than  others  to  grow 
certain  kinds  of  crops.  These  observations  naturally 
have  led  to  what  is  called  "wheat  soil,"  "barley  soil," 
"rye  soil,"  etc.  While  these  observations  on  the  face 
of  them  would  lead  one  to  think  that  some  soils  are 
more  adapted  than  others  for  crop  growing,  there  is  a 
great  deal  of  doubt  as  to  their  real  merit  because  in  the 
light  of  present-day  experiments  crops  have  been  grown 
in  pure  sand  which  had  been  supplied  with  the  plant 
food  elements  and  the  amount  of  moisture  necessary  to 
grow  plants. 

Climatic  conditions  have  much  to  do  with  crop  grow- 
ing, consequently,  when  one  begins  to  study  what  crops 
that  soil  is  to  produce,  he  must  take  into  consideration 
the  climatic  conditions  as  well  as  the  soil.  Naturally 
then,  if  a  farmer  can  supply  a  soil  with  conditions 
equivalent  to  climate,  he  can,  to  the  extent  of  that 
ability,  grow  plants  in  any  soil. 

The  wheat  and  oat  plants  offer  an  interesting  illus- 
tration of  this  fact.  Assuming  that  the  proper  fertility 
is  in  the  soil,  whether  it  is  sand  or  clay,  climatic  con- 
ditions, that  is,  temperature  and  water,  must  determine 
the  growth.  Up  to  the  time  of  ear  shooting  wheat 
needs  wet,  but  not  too  warm  weather;  at  flowering 


SOIL  TEMPERATURE 


33 


time,  dry,  warm  weather;  during  the  ripening  period, 
medium  moist  weather,  and  dry  weather  for  harvest. 
The  oat  does  best  in  moist  and  relatively  cool  weather. 

It  is  not  to  be  supposed  that  it  is  possible  for  a  man 
to  control  the  temperature  of  the  soil  to  the  degree  that 
he  can  bring  about  climatic  conditions  for  growing  a 
crop,  but  by  the  proper  conservation  of  moisture  and 
cultivation  of  the  soil  it  can  be  made  warm  in  the  spring 


Ground  in  this  condition  becomes  too  hot  in  the  summer  for  the  suc- 
cessful development  of  nitrates  for  growing  corn.  This  soil,  a  silt  loam, 
requires  very  careful  handling  to  prevent  its  powdering. 


when  it  otherwise  would  be  cool,  and  cool  in  the  summer 
when  it  otherwise  would  be  hot.  To  this  extent  the 
temperature  of  the  ground  can  be  controlled.  This 
aids  very  materially  in  the  growing  of  crops.  The 
means  for  bringing  this  about  center  around  the  amount 
of  moisture  in  the  ground  and  the  rapidity  with  which  it 


34  THE  OLIVER  PLOW  BOOK 

is  permitted  to  evaporate.  The  evaporation  of  moist- 
ure is  determined  by  the  kind  of  soil,  its  compactness, 
the  amount  of  surface  exposed  to  the  rays  of  light,  and 
the  wind.  The  greatest  difference  in  temperature 
between  the  different  types  of  soil  takes  place  in  the 
early  spring  thawing  and  the  period  immediately  follow- 
ing. This  is  of  utmost  importance  to  farmers  especially 
at  planting  time  because  a  small  amount  of  difference 
in  the  temperature  of  the  ground  means  speeding  up  or 
retarding  the  rate  of  germination  of  the  seed  and  the 
growth  of  the  plants.  Other  things  being  equal,  it 
logically  follows  that  the  sandy  types  of  soil  can  be 
planted  earlier  in  the  year  than  the  clay  types. 

When'  a  soil  is  cultivated  a  larger  area  of  its  surface 
is  exposed,  thus  the  amount  of  evaporation  is  very  much 
greater.  The  result  of  greater  evaporation  is  that  the 
temperature  of  the  cultivated  soil  rises  much  higher  and 
faster  than  that  of  the  uncultivated,  and  permits  earlier 
planting.  This  is  one  of  the  strongest  arguments  for 
fall  plowing  and  leaving  the  ground  rough.  In  the 
spring  of  the  year  the  additional  exposed  surface  dries 
out  much  more  rapidly  and  thus  permits  earlier  seeding. 
The  most  interesting  part  of  this  process  is  that  as  soon 
as  a  dry  mulch  of  this  earth  is  formed  on  the  plowed 
soil  the  loss  of  water  by  evaporation  is  reduced  very 
much,  while  the  loss  on  the  unplowed  soil  is  still  greater. 
In  the  summer  this  reduces  the  temperature  of  the 
mulched  ground,  while  that  of  the  unplowed  ground  is 
considerably  raised. 

A  further  observation  is  that  the  heat  which  is  not 
utilized  in  the  evaporation  of  water  is  being  rapidly 
conducted  downward  in  the  unplowed  ground,  thus 
causing  it  to  dry  out  at  great  depth.  On  the  cultivated 


SOIL  TEMPERATURE  35 

or  mulched  land  only  a  small  part  of  the  heat  is  con- 
ducted downward.  The  other  is  radiated  back  to  the 
atmosphere  by  the  dry  ground  on  top.  This  is  because 
the  mulch  breaks  up  capillary  attraction  with  the  moist 
soil  below,  acting  somewhat  as  a  blanket  to  hold  the 
moisture  down  and  keep  the  heat  out.  When  this  mulch 
becomes  completely  dry,  as  it  often  does,  during  the  hot 
summer,  it  radiates  back  large  amounts  of  excessive 
heat  to  the  atmosphere,  thus,  we  find  the  effect  of  this 
mulch  upon  the  soil  as  follows: 

It  prevents  the  soil  from  reaching  a  high  temperature 
during  the  day  and  a  low  temperature  during  the  night; 
it  greatly  warms  the  soil  in  the  spring;  it  tends  to  con- 
serve moisture  in  the  lower  strata  and  consequently 
reduces  the  rate  of  cooling  in  the  summer.  The  im- 
portance of  this  is  very  manifest  when  one  considers  the 
temperature  necessary  for  the  development  of  nitric  acid. 

Soluble  nitrates  do  not  form  at  a  temperature  below 
41°  Fahrenheit.  The  most  favorable  temperature  is 
between  60°  and  85°  Fahrenheit.  They  form  very 
slowly  at  115°  and  at  130°  will  not  form.  It  has  been 
determined  that  wheat  germinating  at  a  temperature  of 
40°  Fahrenheit  is  more  resistant  to  cold  than  wheat 
which  germinates  at  64°.  Obviously,  the  temperature 
for  the  greatest  formation  of  nitrates,  which  are  neces- 
sary for  the  development  of  plant  food,  is  too  high  for 
the  successful  growing  of  wheat  to  withstand  the  winter's 
freezing.  This  makes  it  necessary,  if  the  most  favorable 
condition  for  wheat  is  to  be  brought  about,  to  plow  the 
ground  and  keep  the  seed  bed  at  a  temperature  of  from 
60°  to  85°  Fahrenheit  in  order  that  plant  food  may  be 
developed  for  the  growing  of  plants  which  must  be 
grown  at  a  cooler  temperature. 


CHAPTER  V 

Why  Soils  Must  Be  Handled 
Differently 

THE  soil  is  the  farmer's  working  capital.  It  is  neces- 
sary that  this  capital  be  used  in  the  wisest  possible 
manner  to  earn  the  profit  which  justly  belongs  to  him. 
Carelessly  handling  the  soil  results  in  a  loss  just  exactly 
in  the  same  manner  as  the  mishandling  of  working 
capital  results  in  loss  to  a  manufacturer.  The  broad 
business  principle  underlying  manufacturing  and  farm- 
ing is  identical  but  the  tools  and  working  capital  of  the 
two  are  widely  separate  and  hence  must  be  handled  in  a 
manner  peculiar  to  each  before  either  can  achieve 
success. 

Soil  is  a  combination  of  disintegrated  rocks,  dead  vege- 
tation and  many  living  forms,  such  as  bacteria  and 
fungi.  Broadly  speaking,  soil  may  be  regarded  as 
matter  in  which  a  planted  seed  can  grow  to  maturity. 
The  difference  between  soil  and  earth  or  ground,  from  a 
practical  standpoint  is  so  slight  that  the  terms  are 
almost  synonymous. 

When  comparing  the  mode  of  life  of  the  plant  with 
that  of  a  human  being,  the  soil  around  the  plant  may  be 
regarded  as  the  dining  room  in  which  the  plant  eats,  the 
kitchen  in  which  its  food  is  prepared,  the  storehouse 
where  the  food  elements  are  kept  in  reserve,  a  reservoir 
for  the  water  and  a  ventilating  system.  When  one 
reflects  upon  the  numerous  results  this  working  capital 
is  supppsed  to  produce,  the  more  concerned  one  becomes 
as  to  how  it  should  be  treated. 


38  THE  OLIVER  PLOW  BOOK 

It  is  plainly  evident  that  all  these  conditions  are 
necessary  to  bring  about  plant  growth.  When  we 
understand  that  plant  growth,  in  the  form  of  either 
legitimate  crops  or  weeds,  consumes  plant  food,  or 
fertility  and  the  water  which  is  contained  in  the  soil, 
we  see  why  it  is  necessary  to  replenish  the  fertility  and 
change  the  condition  in  this  ground  before  new  develop- 
ment of  plant  food  will  take  place.  Plowing  is  the  only 
means  known  to  human  endeavor  that  will  successfully 
start  this  process.  It  is  highly  important  then,  that 
one  should  understand  the  peculiarity  of  the  soil  he 
desires  to  plow  before  he  can  do  this  efficiently. 

There  is  scarcely  a  farm,  regardless  of  how  small  it 
may  be,  that  is  made  up  of  less  than  two  distinct  soil 
compositions.  The  fact  that  most  farms  are  made  up  of 
several  soils,  some  of  them  radically  different,  means 
the  necessity  for  a  thorough  understanding  of  the  types 
because  they  must  be  handled  in  an  entirely  different 
manner  to  bring  about  good  results. 

There  are  many  soil  combinations  but  the  most 
common  are  clay,  loam,  clay  loam,  sandy  loam,  loamy 
sand,  sand  and  muck.  We  will  go  into  some  detail  in 
the  clay,  loam  and  sandy  soils  because  they  are  by  far 
the  most  common  and  will  serve  as  illustrations  of  the 
fact  that  each  soil  must  be  tilled  according  to  its  kind. 
Indeed,  there  are  many  types  of  soils  that  are  never 
mentioned  in  books  which  have  bountifully  repaid  the 
tillage  of  farmers  who  studied  their  characteristics,  and 
by  long,  bitter  experience  learned  how  to  handle  them 
for  crop  growing. 

Clay  is  the  hardest  soil  to  till  on  account  of  the 
peculiar  effect  water  and  air  have  upon  it.  It  holds 


DIFFERENT  HANDLING  OF  SOILS 


39 


This  sample  of  clay  and  the  soils  illustrated  on  pages  41,  43, 
45  and  47  were  taken  from  the  same  farm,  comprising  240  acres. 
These  entirely  different  soils  coming  from  one  farm  offer  the  strongest 
evidence  that  every  farmer  should  thoroughly  understand  soil  composi- 
tion. A  careful  examination  will  reveal  the  similarity  of  the  speci- 
mens to  the  land  being  plowed. 


The  same  peculiarities  of  the  clay  soil  in  this  plowed  ground  obtain  in 
the  specimen  above.     Finely  pulverized  earth  is  not  to  be  seen. 


moisture  longer  than  any  other  kind  of  soil  with  the 
possible  •  exception  of  peat;  bakes  hardest;  forms 
clods  easiest  and  cracks  into  deeper  fissures,  per- 


40  THE  OLIVER  PLOW  BOOK 

mitting  great  quantities  of  moisture  to  escape. 
Clay  never  works  up  into  a  loose,  mellow  seed 
bed,  but  rather  one  of  clods  or  fine  dust  which 
blows  easily.  Cultivated  when  wet,  clay  forms  into 
clods  of  different  sizes,  from  that  of  a  walnut  to  as 
large  as  a  person's  head,  depending  upon  the  kind  and 
amount  of  cultivation.  The  grain  is  fine  and  has  a 
peculiarity  not  discernible  in  any  other  type  of  soil. 
Moist  clay  is  soft  and  sticky.  It  can  be  kneaded  and 
formed  into  various  shapes  and  bodies.  Small  boys, 
unable  to  buy  marbles,  use  clay  very  successfully  for 
making  them.  A  small  piece  of  clay  can  be  easily 
smoothed  and  polished  by  the  fingernail.  While  polish- 
ing a  greasy  or  soapy  feeling  will  be  noted.  Moist  clay, 
when  rubbed  between  the  thumb  and  finger,  has  a  slip- 
pery feeling.  Persons  walking  on  a  sloping  bank  of 
wet  clay  are  apt  to  have  their  feet  slide  out  from  under 
them  very  suddenly.  Clay  in  a  powdered  condition 
when  moistened,  has  a  peculiar  odor  unlike  anything 
else.  Clay  in  color  may  be  red,  yellow,  blue,  white, 
black  or  chocolate. 

For  the  most  part  clay  soils  when  plowed  too  dry, 
form  large  clods  which  are  decidedly  hard  to  break  into 
pulverized  condition.  If  such  soil  lacks  humus  in 
sufficient  quantities  to  keep  it  friable,  it  nearly  always 
forms  a  powdered  surface.  Among  these  peculiarities 
of  clay  the  fact  that  it  holds  moisture  longest,  bakes 
hardest,  and  forms  clods  easiest  should  be  a  warning  that 
the  greatest  of  care  must  be  exercised  in  plowing  dry 
clay  soils,  if  there  is  a  possibility  of  rainy  weather  com- 
ing between  the  time  of  plowing  and  planting,  because 
the  dry  soil  in  this  powdered  condition  will  run  into  a 
sticky,  plastic  mass  which  will  later  dry  hard  and  crack 


DIFFERENT  HANDLING  OF  SOILS 


41 


In  this  specimen  of  clay  loam  soil  the  peculiarities  of  clay  predominate 
but  the  smaller  clods  to  the  right  show  that  this  soil  can  be  pulverized 
more  effectively  than  the  clay  soil. 


The  finer  pulverized  earth  distinguishes  this  clay  loam  from  the  clay 
soil,  but  many  of  the  distinguishing  characteristics  of  clay  can  be  readily 


seen. 


so  that  it  cannot  be  broken  up  successfully  by  any  kind 
of  cultivation.  This  peculiarity  of  clay  has  led  many 
farmers  to  ridicule  so  called  scientific  methods  of  farm- 


42  THE  OLIVER  PLOW  BOOK 

ing  because  they  were  told  that  it  was  impossible  to 
disk  or  harrow  too  much.  A  winter's  freezing  is  the 
only  successful  treatment  for  rectifying  the  evil  done  by 
plowing  a  dry,  clay  soil  lacking  in  humus  and  within  the 
limit  of  abundant  rainfall  and  planting  the  crop. 
Farmers  who  live  in  climates  where  there  is  no  oppor- 
tunity for  freezing  can  ponder  with  a  great  deal  of 
profit  upon  this  problem. 

It  is  common  knowledge  that  a  soil  plowed  wet  will 
dry  out  more  rapidly  than  unplowed  soil.  Plowing  wet 
clay  has  the  same  effect  that  plowing  a  wet  sand  soil  has 
as  far  as  the  drying  out  is  concerned  but  with  entirely 
different  results.  Clay,  being  of  a  plastic  nature  and 
sticking  close  together,  is  puddled  by  wet  plowing.  It  is 
turned  over  in  a  closely  compacted  manner  so  that  the 
top  drys  out  first  leaving  a  slower  drying  process  for  the 
bottom  of  the  furrow.  This  naturally  means  that 
avenues  of  escape  must  be  formed  for  the  moisture  below. 
These  avenues  will  appear  at  the  place  of  least  resistance 
in  the  soil.  These  places  are  caused  by  the  action  of 
the  mouldboard  in  turning  over  the  soil.  The  result  is 
a  cloddy  formation  at  the  bottom  of  the  seed  bed  which 
locks  up  the  soil  fertility  in  the  clods,  interferes  with  the 
upward  trend  of  capillarity  and  makes  absolutely  im- 
possible a  final  preparation  of  the  seed  bed.  The  plow 
mouldboard  working  in  wet  clay  performs  exactly  the 
same  operation  as  a  brick  making  machine  does  in 
molding  the  clay  into  bricks,  hence  in  the  handling  of 
clay  soils  the  plowing  must  be  done  at  a  season  of  the 
year  when  clods  will  not  be  formed. 

When  one  considers  that  clay  soil  holds  moisture 
longer  than  any  other  type  of  soil  it  is  obvious  that  clay 


DIFFERENT  HANDLING  OF  SOILS 


43 


This  specimen  of  loamy  soil  does  not  reveal  either  of  the  character- 
istics of  the  clay  or  the  sand  but  does  show  a  combination  of  the  two  in 
such  form  as  to  make,  this  soil  readily  tillable. 


Observe  in  this  plowing  the  absence  of  large  clods  and  the  same  granular 
tpearance  that  is  plainly  noticeable  in  the  illustration  above. 


appearance 

land  tilled  in  such  a  way  as  to  conserve  moisture  will 
stand  drouth  much  better  than  coarser  grained  soils. 

Fall  plowing  of  clay  soils  in  climates  where  the  ground 
freezes  deep  enough  to  separate  the  soil  particles  is 
becoming  more  generally  practiced.  The  reason  is  that 


44  THE  OLIVER  PLOW  BOOK 

whether  or  not  the  ground  is  in  ideal  condition  for  plow- 
ing in  the  fall  it  can  be  turned  over  covering  up  the 
vegetation  so  that  it  will  rot  during  the  winter,  and  in 
the  spring  when  the  ground  thaws  the  soil  will  be  in 
condition  for  the  successful  making  of  a  seed  bed  pro- 
viding it  is  not  harrowed  when  wet.  Care  must  be 
exercised  however,  in  fall  plowing  of  clay  soils,  to  leave 
the  ground  rough  because  if  it  is  left  in  a  smooth  con- 
dition the  surface  soil  will  run  together  by  the  action  of 
the  water  in  the  spring,  bake,  and  form  a  crust  that  will 
be  difficult  to  handle.  The  principle  underlying  all  this 
is  simply  the  importance  of  permitting  the  surface 
moisture  to  escape  and  holding  that  which  is  below  in 
the  ground.  If  this  idea  is  thoroughly  understood  the 
handling  of  clay  soils  need  not  necessarily  be  difficult, 
but  one  must  have  enough  power  on  his  farm  and  the 
right  kind  of  plow  to  do  this  work  when  moisture  con- 
ditions are  right.  The  unfortunate  part  of  putting  off 
plowing  clay  soils  until  spring  is  that  the  farmer  is  taking 
one  of  three  chances.  The  soil  may  be  ideal  for  plowing, 
it  may  be  too  dry  or  it  may  be  too  wet.  When  the  soil 
is  ideal  everything  is  propitious,  no  damage  done.  When 
the  ground  is  too  dry  it  is  impossible  to  make  an  ideal 
seed  bed  on  account  of  one  of  the  two  extremes — the 
ground  plows  up  into  either  hard  clods  or  fine  dust. 
When  the  ground  is  too  wet  the  condition  that  has  been 
mentioned  previously  in  reference  to  puddling  of  clay 
soils  obtains.  It  is  doubtful  whether  one  would  take 
such  chances  if  he  thoroughly  understood  the  damage 
he  is  doing  by  postponing  the  plowing.  Of  course,  the 
argument  that  farmers  do  not  have  time  to  fall  plow 
every  year  carries  a  great  deal  of  weight  because  it  is 
absolutely  true.  But  why  is  it  not  possible  to  plan  a 
crop  routine  in  which  this  principle  is  taken  into  con- 


DIFFERENT  HANDLING  OF  SOILS 


45 


In  this  specimen  of  sandy  loam  traces  of  the  clay  are  noticeable  but 
the  sand  predominates.  Obviously  the  selection  of  a  plow  for  turning 
this  type  of  soil  must  be  different  from  that  used  in  plowing  clay  soils. 


Observe  the  characteristics  of  the  'sandy  loam  soil  in  this  picture,  and 
also  the  different  manner  in  which  the  furrows  are  laid  from  that  shown 
in  the  plowing  of  clay  on  page  thirty -nine. 


sideration?  A  great  many  farmers  are  now  following 
such  plans  and  the  results  show  the  wisdom  of  this 
practice. 

Loamy  soils  are  made  up  of  sand  and  clay  in  such 
composition  that  the  identity  of  each  is  lost.  When  pressed 


46  THE  OLIVER  PLOW  BOOK 

between  the  thumb  and  finger  a  granular,  raw  feeling  is 
distinctly  noticeable.  It  has  neither  the  rough,  gritty 
feeling  of  the  sand  nor  the  smooth,  slippery  feeling  of 
the  clay.  A  ball  of  dry  loam  is  porous  while  a  ball  of 
dry  clay  is  compact.  Loam  crumbles  readily,  making 
it  easy  to  plow  and  cultivate.  It  dries  out  faster  than 
clay,  and  slower  than  sandy  soils.  It  does  not  form 
hard,  unbreakable  clods  like  clay,  nor  does  it  crumble  so 
easily  as  sand.  It  forms  into  a  mellow,  compact  seed 
bed,  and  gives  the  farmer  more  return  for  poor  cultiva- 
tion than  any  other  soil.  These  characteristics  of  loam 
undoubtedly  give  rise  to  the  statement  that  anyone  can 
throw  seed  into  the  ground  and  it  will  grow,  meaning,  of 
course,  that  anyone  can  farm.  . 

The  expression,  clay  loam,  means  that  the  clay  pre- 
dominates in  the  composition,  and  sandy  loam  means 
that  the  sand  predominates  in  the  composition,  there- 
fore, the  handling  of  a  loamy  soil  must  be  more  inclined 
towards  the  soil  which  predominates.  That  is,  a  clay 
loam  soil  should  be  handled  more  like  a  clay  soil  and  a 
sandy  loam  should  be  treated  more  like  sandy  soil. 
Clay  loam  is  much  easier  to  plow  and  cultivate  than 
clay  because  the  sand  in  the  loam  breaks  up  the  com- 
pact relationship  between  the  clay  particles.  It  has 
much  the  same  texture  as  clay  soil.  It  can  be  worked 
to  better  advantage  than  clay  soil  when  wet,  although 
not  successfully.  It  forms  a  more  compact  and  mellow 
s*eed  bed.  The  cloddy  formation  is  less  predominant 
than  in  clay.  It  has  the  clay  characteristics  of  cracking 
and  drying  out  and  must  be  handled  in  such  a  way  as  to 
prevent  this. 

Sandy  loam  can  be  told  very  readily  by  its  grain. 
Sometimes  the  particles  are  large  enough  to  be  easily 


DIFFERENT  HANDLING  OF  SOILS 


47 


This  specimen  of  sandy  soil  shows  how  quickly  it  dries  out.  The 
blurred  portion  to  the  right  was  caused  by  the  soil  drying  and  falling 
at  the  moment  the  photographer  was  exposing  the  negative. 


In  this  illustration  of  plowing  sandy  soil  the  furrows  are  regular  in 
shape  from  one  end  to  the  other.  The  finely  pulverized  ground  is  just 
as  noticeable  in  the  plowed  field  as  in  the  specimen  shown  above. 


48  THE  OLIVER  PLOW  BOOK 

seen  by  the  naked  eye.  They  can  always  be  distin- 
guished by  the  use  of  a  magnifying  glass.  A  sandy, 
gritty  feeling  is  noticeable  when  rubbing  the  soil  between 
the  thumb  and  finger.  This  is  a  never-failing  way  of 
recognizing  a  sandy  soil  of  any  character.  The  sandy 
loam,  as  the  name  signifies,  is  a  mixture  of  sand  and 
clay,  with  the  sand  in  larger  quantity  than  the  clay. 
This  makes  it  a  less  porous  soil  than  the  loamy  sand, 
but  more  porous  than  clay.  It  works  up  easily, 
does  not  form  hard,  unbreakable  clods,  and  is  particularly 
well  adapted  to  the  growth  of  tuber  crops.  It  does  not 
require  so  much  effort  to  plow  or  work  up  into  a  seed 
bed  as  clay  loam,  but  requires  more  effort  than  the 
loamy  sand. 

Loamy  sand  is  a  combination  of  sand  and  loam  in 
different  degrees  than  sandy  loam.  Sandy  loam  con- 
tains more  loam  than  sand,  and  loamy  sand  more  sand 
than  loam.  The  easiest  and  best  way  to  distinguish  be- 
tween these  two  types  of  soil  is  to  make  them  into  balls. 
The  sandy  loam  will  hold  its  shape,  while  the  loamy  sand 
will  not.  Loamy  sand  dries  out  the  quickest  of  any 
type  of  soil.  It  is  the  easiest  to  plow,  it  never  forms 
clods,  is  coarse  grained,  and  is  easily  distinguished  by 
the  gritty  feeling  experienced  by  rubbing  it  between  the 
thumb  and  forefinger.  It  is  a  soil  that  has  to  be  handled 
with  the  greatest  of  care  or  it  will  produce  nothing.  It 
readily  blows  on  account  of  the  rapidity  with  which  it 
dries  out. 

The  grains  of  sand  are  much  coarser  than  particles  of 
clay.  Obviously,  there  will  be  larger  air  spaces.  These 
air  spaces  permit  moisture  to  percolate  downward  rapid- 
ly. Sand,  in  a  loose  condition  is  thus  easily  packed  by  a 
heavy  rain.  The  water  percolating  downward  naturally 


DIFFERENT  HANDLING  OF  SOILS  49 

carries  with  it  the  grains  of  sand  until  they  strike  other 
grains  and  cannot  be  carried  farther.  Thus,  the  process 
continues  until  the  final  arrangement  of  all  the  soil 
grains  is  such  that  there  is  no  further  opportunity  for 
the  force  of  gravity  to  operate.  This  principle  must  be 
carried  constantly  in  mind  when  farming  sandy  soils 
because  the  water  compacting  the  soil  in  this  manner  on 
its  downward  trend  makes  the  finest  capillary  connec- 
tion possible  between  the  top  of  the  ground  and  the 
lower  surface.  Thus,  when  the  weather  warms  to 
such  an  extent  that  water  vaporizes  on  the  surface, 
moisture  is  drawn  from  below  by  capillary  attraction 
with  great  rapidity.  The  only  way  that  this  can  be 
stopped  is  by  changing  the  relationship  of  the  soil 
particles  on  the  surface.  This  can  be  brought  about  by 
the  use  of  any  implement  that  will  stir  the  soil.  What- 
ever implement  is  used,  the  relationship  of  the  soil 
particles  must  be  entirely  changed  so  that  the  moisture 
from  below  cannot  escape  into  the  air  by  capillary  at- 
traction. 

With  this  understanding  it  naturally  follows  that 
sandy  soils  require  more  frequent  liming,  fertilizing  and 
a  greater  amount  of  humus  than  the  clay  soils,  also  more 
frequent  cultivating  on  the  surface  if  one  expects  to  get 
the  most  out  of  them.  A  question  often  arises  as  to  the 
advisability  of  plowing  sandy  soils  in  the  fall  for  spring 
planting.  These  water  peculiarities  of  sandy  soils 
make  a  great  difference  between  the  time  of  plowing  and 
the  planting  season.  In  the  chapter  on  the  temperature 
of  the  soil,  reasons  are  given  as  to  why  sandy  soil  be- 
comes warmer  earlier  in  the  spring  than  clay  soil.  This 
earlier  warming  of  sandy  soil  and  the  quickness  with 
which  the  soil  compacts  offer  good  reasons  for  per- 


50  THE  OLIVER  PLOW  BOOK 

mitting  a  much  shorter  time  between  the  plowing  of  the 
ground  and  the  planting  of  the  crop. 

The  practice  of  growing  a  green  cover  crop  of  some 
sort  and  plowing  it  under  in  the  spring  of  the  year 
instead  of  in  the  fall  is  proving  to  be  a  very  beneficial 
and  profitable  process  for  sandy  land,  particularly  if 
those  cover  crops  are  nitrogen  bearing  plants,  such  as 
clover,  etc.,  simply  because  being  plowed  under  in  sandy 
soil,  they  form  a  sort  of  reservoir  for  holding  moisture  as 
well  as  yielding  nitrates.  The  fact  that  sand  does  not 
form  clods  or  large  air  spaces  makes  a  practice  of  this 
kind  profitable  on  sandy  soils  in  the  spring  whereas  it 
would  prove  detrimental  on  clay  soils  on  account  of  the 
tendency  of  these  soils  to  form  clods  and  air  spaces  on 
the  bottom  of  the  seed  bed. 


CHAPTER  VI 
Depth  of  Plowing 

DEPTH  of  plowing  has  been  argued  pro  and  con  for 
many  years.  A  depth  of  six  inches  is  regarded  as  deep 
plowing  by  some  and  shallow  by  others.  In  this  dis- 
cussion two  to  four  inches  is  regarded  as  shallow.  faur_ 
to  eight  inches  as  medium  and  eight  to  sixteen  inches  as 
deep  plowing.  The  question  that  interests  every 
farmer  and  one  that  he  must  decide  for  himself  is  whether 
he  shall  practice  shallow  or  deep  plowing  on  his  farm, 
and  not  what  his  neighbor  regards  as  deep  or  shallow 
plowing.  One  farmer  makes  great  success  of  deep 
plowing,  another  plows  just  as  deep  and  meets  with 
dismal  crop  failure.  One  farmer  plows  deep  in  the  fall 
and  grows  a  good  crop  the  next  year,  another  plows  just 
as  deep  in  the  fall  and  has  a  dismal  failure  the  next  year. 
The  same  results  are  happening  in  deep  spring  plowing. 
These  being  facts  beyond  dispute,  something  besides  the 
mere  act  of  plowing  must  be  taken  into  consideration 
before  a  conclusion  can  be  reached. 

Advocates  of  deep  fall  plowing  center  their  arguments 
around  the  theory  that  deep  plowing  in  the  fall  turns 
the  raw  earth  to  the  surface  giving  it  the  advantage  of 
the  winter's  freezing  and  atmospheric  influences  to  bring 
into  play  the  fertility  which  is  supposed  to  have  lain 
dormant  or  in  unavailable  form.  The  experience  of 
those  who  have  deep  fall  plowed  with  disastrous  results 
the  next  year  would  tend  to  disprove  this  theory.  The 
fact  that  many  men  have  deep  plowed  in  the  spring  with 
successful  results  would  tend  furthermore  to  prove  that 
fertility  is  made  available  by  deep  plowing  in  the  spring. 


52  THE  OLIVER  PLOW  BOOK 

These  observations  tend  to  the  belief  that  those  who 
plow  deep  in  the  fall  with  bad  results  the  next  year, 
must  not  have  had  fertility  on  the  surface  of  the  plowed 
field  or  the  winter's  freezing  destroyed  it,  and  further 
that  the  deep  plowed  field  in  the  spring  contains  fertility. 

If  one  regards  these  deductions  as  logical,  the  question 
as  to  whether  one  should  plow  deep  or  shallow  in  the 
fall  or  spring  must  be  solely  determined  by  the  condition 
of  the  land.  The  farmer  must  be  absolutely  certain  that 
he  has  the  plant  food  elements  in  the  soil  either  in  avail- 
able or  unavailable  form,  and  also  whether  freezing 
influences  are  necessary  for  the  liberation  of  that  food. 
How  can  this  be  determined? 

It  is  doubtful  whether  samples  taken  from  the  surface 
of  a  plowed  field  and  examined  by  a  soil  chemist  would 
be  of  any  practical  value  to  the  farmer  for  the  simple 
reason  that  the  soil  chemist  would  be  unable  to  tell  as 
to  the  availability  of  these  elements  in  the  soil.  The 
most  the  chemist  can  do  is  to  determine  the  amount  and 
kinds  of  elements  that  are  in  the  sample  submitted. 
These  deductions  are  apt  to  be  entirely  wrong  as  far  as 
the  quantity  over  the  whole  field  is  concerned. 

It  is  a  question  whether  any  man  by  following  this 
method  can  ever  be  sure  as  to  what  the  soil  needs  on 
account  of  the  uncertainty  of  the  amount  of  plant  food 
elements  of  all  kinds  existing  in  different  portions  of  the 
field.  A  much  better  way  for  a  farmer  who  is  not 
positive  as  to  what  he  is  going  to  accomplish  by  deep 
plowing  is  to  do  a  little  experimenting  of  his  own.  It 
can  be  done  very  successfully  providing  the  experimenter 
has  learned  how  to  handle  the  different  soils  as  discussed 
in  Chapter  V. 


DEPTH  OF  PLOWING  53 

Take  five  potfuls  of  soil  from  the  field  and  test  for 
the  elements  required  to  grow  the  crop.  In  each  of 
these  pots  plant  a  few  seeds  of  the  crop  desired  to  be 
grown.  To  the  first  pot  add  nothing,  to  the  second,  a 
quarter  teaspoonful  of  sulphate  of  potash,  or  if  that  is 
not  obtainable  use  a  teaspoonful  of  wood  ashes.  To  the 
third  pot  put  a  combination  of  the  phosphate  and 
potash,  to  the  fourth  a  quarter  teaspoonful  of  sodium 
nitrate  or  ammonium  sulphate,  and  to  the  fifth  a  com- 
bination of  acid  phosphate,  sulphate  of  potash  and 


Whether  the  ground  is  plowed  deep  or  shallow  the  condition  of  the 
earth  shown  in  this  cross  section  of  a  plowed  field  must  obtain  before  the 
seed  bed  can  be  made  a  success.  Deep  plowing  often  shows  a  good 
surface  and  hides  a  bad  furrow  bottom. 


sodium  nitrate.  This  sort  of  test  is  not,  strictly  speak- 
ing, scientifically  accurate,  but  it  is  close  enough  to  show 
anyone  which  of  the  three  principal  plant  food  elements, 
phosphorus,  potash  and  nitrogen,  are  lacking  in  the  soil. 

If  the  plant  in  the  first  pot  refuses  to  grow,  it  is  plainly 
evident  that  the  soil  is  lacking  in  plant  food  elements. 
The  growth  of  the  plants  in  each  of  the  pots  will  signify 
in  what  the  soil  is  lacking  and  what  will  be  necessary  to 


54  THE  OLIVER  PLOW  BOOK 

add  to  that  soil  before  it  will  produce.  It  is  further 
logical  to  assume  that  if  the  best  growth  takes  place  in 
those  pots  that  contain  fertilizer  or  the  plant  food 
elements  which  the  farmer  cannot  hope  to  add  to  the 
soil,  it  is  unwise  to  plow  the  ground  to  that  depth  whether 
he  does  it  in  the  fall  or  spring.  We  often  deceive  our- 
selves into  thinking  that  soil  plowed  eight,  nine,  or  ten 
inches  deep  turns  up  soil  fertility  when  it  does  not. 

As  far  as  the  writer  has  been  able  to  learn,  there  have 
never  been  experiments  tried  to  prove  that  winter's 
freezing  unlocks  soil  fertility  any  more  than  that  the 
winter's  freezing  of  certain  soil  particles  such  as  clay, 
has  a  tendency  to  flocculate  the  soil,  or  break  it  into 
small  particles,  so  that  the  fertility  contained  in  the  soil 
is  made  more  available. 

Obviously  then,  one  must  suppose  that  before  deep 
fall  *  or  "spring  plowing  is  indulged  in  it  is  necessary  to 
know  whether  the  deep  soil  contains  available  fertility. 

The  other  important  question  to  decide  is  whether  or 
not  the  plowing  can  be  done  so  as  to  leave  the  ground  in 
the  proper  tilth  and  condition  for  plant  growth.  This 
can  only  be  determined  by  having  a  knowledge  of  the  soil 
and  how  to  handle  it  to  bring  about  conditions  of  tilth. 

The  one  great  advantage  of  deep  fall  plowing  over 
deep  spring  plowing  is  that  the  fall  plowing  receives  the 
aid  of  t'ime,  moisture  and  freezing  to  break  up  cloddy 
formations  that  may  have  resulted  from  the  plowing  and 
to  compact  the  soil  into  a  suitable  condition  for  capillar- 
ity to  take  place.  In  deep  spring  plowing,  the  ground 
is  often  turned  over  in  cloddy  formations  which  are 
detrimental  to  the  compacting  of  the  soil  at  the  bottom 
of  the  furrow  on  account  of  the  depth  at  which  it  must 


DEPTH  OF  PLOWING 


55 


be  worked.  The  result  is  a  seed  bed  with  a  poor  cap- 
illary connection  with  the  sub-surface.  This  fact,  and 
also  the  fact  that  barren  soils  are  often  turned  over 
make  deep  plowing  in  the  spring  questionable  in  a 
great  many  localities,  but  where  the  soil  can  be  turned 
over  in  a  friable  condition  and  contains  abundant  plant 
food,  there  is  little  to  worry  about  deep  plowing  in  the 
spring  providing  the  seed  bed  is  compacted  as  it  should  be. 


This  depth  of  plowing  attempted  with  a  base  designed  for  medium 
depth  plowing  reoeals  a  badly  turned  furrow  slice,  poorly  cleaned  furrow 
bottom.  The  illustration  on  the  next  page  shows  a  side  view  of  this 
plowing. 


56  THE  OLIVER  PLOW  BOOK 

Deep  plowing  cannot  be  done  successfully  with  a  plow 
having  a  capacity  of  not  more  than  seven  or  eight  inches 
in  depth,  because  it  cannot  possibly  break  up  or  pulverize 
'a  deep  furrow\ This  tact  should  be  taken  into  serious 
~cbnsideration~by  anyone  who  attempts  to  do  deep  plow- 
ing if  he  expects  to  plant  a  crop  soon  after  the  plowing 
is  done.  Its  curvature  and  shape  will  permit  the  passage 
of  thick  slices  over  the  mouldboard.  But  when  the 
plow  is  penetrating  a  depth  beyond  its  capacity  it 
pulverizes  poorly  to  that  depth  and  the  rest  of  the  slice 
is  broken  into  clods  which  are  usually  thrown  on  the 
bottom  of  the  furrow.  For  this  reason  one  who  expects 
to  turn  a  depth  of  eight  inches  or  more  should  secure  a 
plow  with  a  bottom  designed  for  this  type  of  plowing. 


Part  of  the  furrow  is  turned  on  edge  and  is  almost  ready  to  fall  back. 

Attempting  to  use  a  plow  having  a  capacity  of  eight 
inches  in  those  soils  that  stick  together  has  a  tendency 
to  set  the  furrow  slice  on  edge  and  oftentimes  the  furrow 
slice  rolls  back  with  the  sod  on  top.  Thus,  the  furrow 
itself  effectively  offsets  any  influence  the  plow  bottom 
may  exercise  towards  pulverization.  This  fact  also 
accounts  for  a  great  deal  of  deep  plowing  failure  because 


DEPTH  OF  PLOWING 


57 


Plowing  eleven  inches  deep  with  a  bottom  made  especially  for  deep 
plowing.  Observe  the  clean  furrow,  smooth  furrow  bottom  and  wall, 
and  the  furrow  slice  turned  over  properly.  This  plowing  is  in  great 
contrast  to  that  illustrated  on  page  fifty-five.  On  account  of  the  depth  at 
which  this  plow  is  wording  the  greatest  of  care  should  be  exercised  to  see 
that  the  bottom  of  the  furrow  is  properly  made  because  none  of  the  after 
preparation  implements  such  as  the  disk  harrow,  peg  harrow,  or  roller 
pulverizer  can  exert  much  influence  on  the  bottom  of  the  furrow. 


the  seed  bed  is  left  in  such  a  manner  that  moisture 
cannot  come  up  from  below  by  capillary  attraction  and 
that  which  is  on  the  surface  either  washes  away  or  sinks 
into  the  subsoil  where  it  cannot  rise  again. 


58 


THE  OLIVER  PLOW  BOOK 


We  must  remember  whether  we  are  plowing  shallow, 
medium,  or  deep  that  the  ground  must  always  be  left  in 
condition  at  the  bottom  of  the  furrow  for  capillarity  to 
take  place  with  the  subsoil.  We  cannot  judge  this  by 
looking  at  the  surface.  It  is  necessary  to  dig  into 
the  ground  the  depth  of  the  plowing  and  observe  the 
condition.  When  we  do  this  we  will  often  see  things 
that  surprise  us,  and  the  explanation  for  many  a  deep 
plowing  failure  can  be  satisfactorily  found. 

The  great  advantage  of  deep  plowing  is  that  it  offers 
deeper  root  beds  for  the  crops.  The  mellower  the 
ground  is  the  easier  the  roots  grow  and  penetrate. 


Side  view  of  the  deep  plowing  with  the  proper  bottom  illustrated  on 
page  fifty-seven.  Observe  how  this  soil  is  being  turned  over.  The 
crack  through  the  center  of  the  furrow  slice  shows  the  immense  pressure 
being  exerted  to  pulverize  the  furrow  slice  from  top  to  bottom.  Observe 
also  in  the  plowed  field  the  lack  °f  large  clods  and  holes.  The  manner 
in  which  this  bottom  forces  the  top  of  the  furrow  slice  against  the  ground 
and  then  crushes  it  as  the  plow  advances  is  obvious. 

With  the  deep  plowing  the  plant  has  the  additional 
advantage  of  getting  farther  into  the  ground,  thus 
enabling  it  to  drink  in  more  plant  food  and  have  the 


DEPTH  OF  PLOWING  59 

advantage  of  more  moisture  in  the  dryer  season  of  the 
year.  This  season  is  nearly  always  the  flowering  time 
of  the  plant,  and  accounts  in  a  large  measure,  for  the 
additional  crops  that  are  grown  on  deeper  plowed  seed 
beds  which  are  properly  compacted  and  cultivated  on 
the  surface  for  the  retention  of  moisture. 

It  is  equally  obvious  that  if  the  deep  plowed  ground 
is  not  compacted  properly  on  the  start  for  the  retention 
of  moisture  and  improperly  cultivated,  or  not  cultivated 
later,  that  the  deeper  the  seed  bed  the  more  moisture 
will  escape. 

Chapter  V  on  handling  soils  brings  out  the  fact  that 
the  water  holding  content  is  determined  by  the  size  of 
the  soil  grains,  hence,  we  can  expect  sandy  soils  to  dry 
out  much  more  rapidly  than  clay  soils  and  thus  produce 
less  unless  the  proper  precautions  are  taken  to  save  the 
moisture. 

Sandy  soils  have  less  fertility  to  turn  up  in  deep  plow- 
ing than  clay  soils,  hence  a  farmer  who  has  any  type  of  a 
sandy  soil  should  be  very  careful  in  his  plowing  to  see 
that  the  plant  food  elements  are  in  the  surface  after  the 
ground  is  plowed  if  he  has  to  put  them  there  by  means 
of  artificial  fertilizers.  The  very  nature  of  sand  prevents 
it  from  puddling  and  forming  clods,  but  is  propitious  to 
the  rapid  escapement  of  moisture. 

A  grave  question  arises  in  deep  plowing  as  to  the 
value  of  spreading  a  heavy  coat  of  manure  on  the  surface 
and  turning  it  under  providing  the  plowing  is  done 
deeper  than  the  habits  or  customs  of  the  roots  of  the 
plant  for  penetrating  the  soil.  If  the  soil  above  the 
spread  manure  contains  sufficient  fertility  to  grow  the 
crop  it  is  easy  for  one  to  deceive  himself  into  thinking 
that  he  has  accomplished  a  great  deal  by  turning  under 


60  THE  OLIVER  PLOW  BOOK 

the  manure.  As  a  matter  of  fact,  any  manure  that  is 
spread  below  the  roots  is  of  little  value  to  the  plants 
because  if  there  is  sufficient  moisture  in  the  ground  to 
raise  what  plant  food  may  come  from  it  in  solution, 
there  will  be  a  sufficient  amount  of  water  in  the  ground 
to  permit  it  to  leach  away,  hence,  the  chief  value  of 
manure  as  fertilizer  is  lost. 

Another  serious  objection  constantly  happening  is 
that  a  very  heavy  coat  of  barnyard  manure  is  applied  and 
turned  under  in  such  a  way  that  nitrates  form  too 
rapidly  in  the  spring  on  account  of  the  ammonia  content 
of  the  manure  and  later  in  the  season  change  into  un- 
available forms  thus  destroying  the  influence  of  the 
manure,  leaving  the  remaining  part  dry  and  in  a  form 
that  is  hard  to  dissolve.  This  is  what  our  scientists 
term  burning  the  soil.  This  dry,  insoluble  form  of 
fertilizer  at  that  depth  in  the  ground  interferes  most 
seriously  with  the  upward  trend  of  moisture  and  retards 
growth  to  that  extent. 

While  there  is  no  question  but  that  ultimately  the  soil 
will  be  benefited  by  turning  under  manure  at  this  depth 
one  can  diminish  a  crop  or  lose  it  by  a  too  zealous  appli- 
cation of  manure  at  this  depth,  particularly  if  the  ap- 
plication is  made  close  to  planting  time. 

It  is  easily  possible  for  a  soil  that  contains  fertility  to 
be  plowed  deep  in  the  fall  and  so  improperly  handled  the 
following  spring  that  a  crop  cannot  grow.  For  this 
reason  if  a  test  with  the  soil  pots  proved  that  there  was 
plenty  of  fertility  in  the  soil  and  the  crop  next  year 
proved  a  failure,  it  naturally  follows  that  the  deep  plow- 
ing in  the  fall  would  not  be  responsible  for  the  failure. 
This  is  not  a  mere  hypothesis  but  has  happened  many 
times  when  the  failure  of  the  crop  has  been  wrongly  at- 


«*     DEPTH  OF  PLOWING  61 

tributed  to  deep  fall  plowing.  The  preparation  of  the 
seed  bed  the  following  spring  was  the  fault.  The  logic  in 
the  reference  to  the  preparation  of  fall  plowed  ground  in 
the  spring  is  just  as  applicable  to  the  deep  fall  plowing  as 
the  medium  depth  plowing  because  air  and  moisture 
must  be  properly  proportioned  the  full  depth  of  the 
seed  bed. 

Another  benefit  that  can  be  derived  from  deep  plow- 
ing is  the  eradication  of  weeds.  Shallow  plowing  very 
seldom  does  anything  except  to  more  effectively  plant 
weed  seeds.  When  plowing  is  done  to  effectively 
bury  all  vegetation  and  seeds  deep  in  the  ground  it  is 
impossible  for  the  majority  of  them  to  sprout  and  reach 
the  surface  before  the  crop  which  is  planted  above  them 
can  sprout  and  reach  a  good  growth.  This  fact  is  due 
to  the  peculiar  nature  of  plant  growth. 

There  is  no  reason  to  believe  that  weeds  should  grow 
any  faster  than  other  plants  unless  conditions  for  their 
growth  are  more  favorable.  This  is  the  reason  why 
certain  kinds  of  grassy  weeds  appear  in  the  blue  grass 
lands  when  the^  blue  grass  itself  is  drying  out  from  lack 
of  moisture.  To  put  it  another  way,  these  grassy 
weeds  flourish  with  less  moisture  than  blue  grass  does. 
To  get  rid  of  weeds  means  to  keep  the  ground  in  a  con- 
dition for  the  more  favorable  growth  of  the  plant  that 
the  farmer  wishes  to  grow. 

Deep  plowing  in  the  spring  of  the  year  puts  the  weed 
seeds  so  far  down  with  the  turned  surface  that  the 
ground  is  cooler  than  that  above,  hence  the  sprouting  of 
the  seed  is  retarded.  If  the  surface  soil  is  cultivated  at 
the  time  it  should  be,  the  surface  of  the  ground  will  be 
warmer  by  the  evaporation  of  moisture  and  the  crop 
can  be  planted  and  receive  a  good  start  before  the  weeds 


62 


THE  OLIVER  PLOW  BOOK 


Plowing  done  in  this  manner  deeply  buries  all  the  trash  in  the  furrow, 
leaving  a  clean  surface  for  the  final  preparation  of  the  seed  bed.  Observe 
the  very  weedy  condition  at  the  left  and  the  entire  absence  of  weeds  pro- 
truding between  the  furrow  slices.  It  is  doubly  essential  in  deep  plow- 
ing that  all  the  weeds  be  entirely  covered  to  prevent  the  formation  of  large 
air  vents  from  the  top  of  the  seed  bed  to  the  bottom. 


can  interfere,  thus  the  weeds  will  start  and  provide  food 
substance  for  the  plants.  The  deep  fall  plowing  of  weedy 
ground  will  naturally  result  identically  the  same  as  the 
spring  plowing,  but  with  this  additional  advantage,  if 
the  ground  is  plowed  sufficiently  early  in  the  fall  and 
enough  rain  falls  the  weeds  will  sprout  and  grow  in  the 
fall  and  be  killed  by  the  winter's  freezing. 


CHAPTER  VII 


When  to  Plow 

THE  reader  who  has  carefully  perused  the  preceding 
pages  has  observed  that  fall  or  spring  plowing  is  not 
an  academic  question  to    be    decided  by  debate.     But 
one  which  must  be  decided  by  every  farmer. 

Enough  has  been  said  to  bring  out  the  important  fact 
that  as  a  rule  clay  soils  are  better  plowed  in  the  fall  and 
sandy  soils  in  the  spring.  However,  many  contributing 
factors  such  as  humus,  freezing,  amount  of  rainfall, 
plowing  under  green  crops,  moisture  conservation  and 
killing  insects  and  weeds  enter  the  problem.  No  man 
except  the  one  who  understands  the  soil  under  consider- 
ation and  purpose  of  plowing  can  give  an  opinion  worth 
while. 

As  a  general  rule  fall  plowed  ground  can  be  worked 
earlier  in  the  spring  than  unplowed  ground.  Nature 
has  a  curious  habit  of  causing  plants  to  grow  and  prosper 
in  certain  seasons  of  the  year.  The  nearer  crops  can  be 
planted  to  that  season  of  growth  the  greater  is  the 
prospect  for  a  successful  crop.  Late  and  backward 
springs  often  prevent  the  planting  of  the  seed  until  quite 
late.  The  fact  that  fall  plowed  ground  left  in  a  rough 
state  dries  out  much  more  rapidly  in  the  spring  than 
unplowed  ground  gives  the  advantage  of  getting  onto 
the  ground  earlier  in  the  year.  This  offsets  in  a  measure, 
the  baneful  influence  of  a  backward  spring  and  also 
enables  the  farmer  to  do  his  disking  and  harrowing 


64  THE  OLIVER  PLOW  BOOK 

oftener  if  necessary  to  put  the  ground  in  a  better  con- 
dition of  temperature  for  the  sprouting  of  the  seed. 

Time  is  the  determining  factor.  Oftentimes  when 
plowing  should  be  done  so  as  not  to  form  clods,  the 
farmer  is  exceedingly  busy  at  some  other  task,  usually 
harvesting  or  cultivating.  Naturally  the  plowing  waits. 

There  is  always  some  season  in  the  year  when  ground 
can  be  plowed  without  the  formation  of  clods.  For  this 
reason  those  who  expect  to  get  the  most  out  of  their 
plowing  will  take  that  into  grave  consideration.  It  is  a 
peculiar  fact  that  plowing  is  usually  done  in  certain 
seasons  of  the  year  because  of  habit  and  necessity. 

No  one  who  contemplates  building  a  house  would  ever 
think  of  laying  the  foundation  in  the  winter  when 
freezing  would  ruin  it  before  the  house  could  be  built. 
It  is  just  as  illogical  to  plow  the  ground  when  it  is  not  in 
condition  for  pulverization  as  it  is  to  lay  a  foundation 
in  the  winter,  providing  Nature  does  not  have  time  to  do 
the  pulverizing  before  the  crop  is  planted. 

This  old  idea  of  spring  plowing,  fall  plowing,  and 
summer  plowing  will  have  to  give  way  to  plowing  when 
the  ground  is  in  proper  condition  for  it,  particularly  in 
the  heavy  types  of  soil,  if  the  crop  is  to  have  the  benefit 
of  the  best  start  possible. 

If  plowing  is  done  at  the  last  minute,  the  ground  is 
either  in  first  class  condition  for  pulverization,  too  wet, 
or  too  dry  and  hard.  The  chances  are  one  in  three  of 
finding  the  ground  fit.  Consequently,  plowing  cannot 
be  put  off  until  spring  or  fall  if  advantage  is  to  be  taken 
of  right  conditions  for  plowing. 

Unfortunately  it  has  been  the  habit  for  years  and 
years  to  put  off  plowing  sod,  cornfields,  and  very  many 


WHEN  TO  PLOW  65 


stubble  fields  until  spring.  In  other  words,  the  bulk  of 
the  plowing  is  left  for  spring  work.  This,  in  the  light  of 
present  day  experiences,  will  have  to  be  entirely  reversed 
or  the  maximum  crops  can  never  be  grown. 

Wet  spring  plowing  of  clay  soils  always  gives  the 
crops  a  poor  start  and  makes  after  cultivation  practically 
impossible  for  the  development  and  liberation  of  plant 
food,  particularly  if  the  cultivating  season  is  dry.  It  is 
a  matter  of  history  that  most  wet  springs  are  followed 
by  dry  summers.  Wet  spring  plowing  of  sandy  soils 
means  the  leaching  away  of  plant  food  elements  that 
should  be  retained  for  the  growing  crop. 

The  plowing  of  clay  soils  in  the  spring  when  they  are 
too  dry  and  hard  means  plowing  either  a  field  of  clods  or 
else  turning  the  soil  into  a  finely  powdered  condition 
which  becomes  plastic  upon  the  first  rain.  Plowing  a 
sandy  soil  when  it  is  too  dry  means  further  escapement 
of  moisture.  Therefore,  plowing  either  when  too  wet 
or  too  dry  in  the  spring  means  a  curtailment  of  the  crop. 

The  following  information  on  corn  and  oat  growing 
shows  why  an  understanding  of  the  crops  to  be  grown 
and  the  physical  condition  of  the  ground  necessary  to 
grow  these  crops  should  be  considered  before  plowing. 

Corn  requires  271  tons  of  water  to  produce  one  ton  of 
dry  substance.  This  means  2.39  acre  inches  of  water. 
In  other  words,  it  requires  2.39  inches  of  water  to  grow 
one  ton  of  corn.  It  has  been  demonstrated  that  too 
little  or  too  much  rainfall  at  flowering  time  is  injurious 
to  the  crop.  If  the  corn  grower  expects  his  crop  to  have 
this  water  just  exactly  as  the  plant  needs  it,  neither  too 
much  nor  too  little  at  any  one  time,  he  must  of  necessity 


66  THE  OLIVER  PLOW  BOOK 

plow  his  ground  and  cultivate  to  keep  the  surplus  away 
from  the  surface,  but  in  such  shape  that  the  plants  can 
draw  upon  it. 

The  illustrations  on  the  opposite  page  are  photo- 
graphs of  an  experiment  to  bring  about  the  value  of 
plowing  in  July  for  fall  wheat.  This  land  was  a  light, 
sandy  and  gravelly  river  bottom  loam  poorly  adapted  to 
small  grains.  The  farm  was  situated  in  the  northern 
part  of  Indiana.  The  field  treated  in  this  manner  showed 
an  increase  of  twenty  per  cent,  over  the  rest  of  the  field 
which  was  plowed  early  in  September  in  the  ordinary 
manner.  The  seeding  and  fertilizing  over  the  entire  field 
were  exactly  alike. 

No.  1 — The  field  plowed  on  July  18.     Observe  the  foul  condition  of 
the  unplowed  ground.     It  is  full  of  milk  weeds  and  dock- 
No.  2 — Later  in  the  day  the  disk  harrow  and  pulverizer  were  called 
into  play  to  put  the  seed  bed  in  shape. 

No.  3 — Observe  that  the  weeds  are  buried  deep  in  the  furrow  and  the 
disked  and  rolled  section  is  compacted  away  from  the  unplowed  section 
showing  that  the  seed  bed  is  compact  from  top  to  bottom. 

No.  4 — Photograph  taken  June  25,  the  following  year.     The  portion 
of  the  field  plowed,  disked  and  rolled.     Observe  the  lack  of  milk  weeds 
and  dock- 
No.  5 — A  few  of  the  wheat  heads  selected  at  random  from  the  field 
shown  in  No.  4.     These  heads  produced  twenty  per  cent,  more  per  acre. 

No.  6— The  section  of  the  field  that  was  plowed  and  harrowed  in  the 
ordinary  manner.  Observe  the  appearance  of  milk  weeds.  This  section 
was  photographed  the  same  day  as  the  field  shown  in  No.  4. 

No.  7 — A  few  of  the  heads  selected  at  random  from  the  portion  of  the 
field  shown  in  No.  6.  Observe  how  much  bigger  and  better  the  heads 
are  in  No.  5. 


68  THE  OLIVER  PLOW  BOOK 

Corn  also  requires  in  the  vicinity  of  three  thousand 
degrees  of  heat  to  complete  the  crop  from  start  to  finish. 
Anyone  can  readily  see  that  if  three  thousand  degrees 
of  heat  were  applied  in  one  stroke  to  the  field  what  would 
happen  to  the  corn.  This  amount  of  heat  must  be 
scattered  over  the  period  through  which  the  corn  grows. 

This  heat  has  to  do  with  the  development  of  plant 
food,  its  conservation,  and  the  ability  of  the  corn  plant 
to  partake  of  that  food.  It  also  has  to  do  with  the 
amount  of  moisture  that  falls  and  is  consumed.  Unless 
ground  is  in  physical  condition  for  heat  to  work  to  the 
best  advantage  in  doing  its  labor  and  also  to  enable 
plant  food  to  develop  as  the  plants  need  it  a  maximum 
crop  cannot  be  grown  regardless  of  how  fertile  the  land 
may  be. 

A  study  of  soil  conditions  has  revealed  that  ground, 
mellow  and  friable,  to  a  depth  of  at  least  six  inches  is 
required  at  the  start  for  bringing  about  the  condition 
mentioned.  Seven  and  eight  inches  have  proven  to  be 
better.  This  naturally  means  that  this  portion  of  the 
ground  cannot  be  full  of  large  and  coarse  dead  vegetation 
in  a  half  decayed  form  because  it  interferes  with  the 
upward  trend  of  moisture  which  is  necessary  if  the  corn 
plant  is  to  receive  the  proper  amount  of  moisture  by 
capillarity  for  the  manufacture  of  plant  food. 

It  naturally  follows  from  this  that  ground  covered 
with  dead  vegetation  for  planting  corn  should  be  plowed 
deep  and  the  vegetation  buried  deep  in  the  ground  so  as 
to  interfere  as  little  as  possible  with  the  upward  trend  of 
moisture. 

It  is  particularly  desirable  in  spring  plowing  to  bury 
this  trash  deep  enough  so  that  it  will  not  pull  out  and 
interfere  with  after  cultivation.  Burying  cornstalks 


WHEN  TO  PLOW  69 


deep  in  the  corner  of  the  furrow  places  them  where  they 
will  do  the  least  possible  damage  in  the  way  of  interfering 
with  capillary  attraction,  where  they  do  not  interfere  with 
after  cultivation  and  in  the  right  place  to  decay  in  the 
soonest  possible  time,  because  the  water  trickling  down 
between  the  furrow  slices  has  an  easy  approach  to  them. 

The  oat  requires  504  tons  of  water  or  4.45  acre  inches 
to  grow  a  ton  of  dry  substance,  and  approximately  2,100 
degrees  of  heat.  The  plant  food  elements  that  enter 
the  make-up  of  the  oat  do  not  require  so  much  heat  for 
their  manufacture  as  those  of  the  corn  plant.  This  has 
led  to  the  statement  that  oats  do  not  require  heat  and 
also  that  oats  do  best  in  a  moist  and  relatively  cool  cli- 
mate. It  naturally  follows  that  if  the  seed  bed  is  put  in 
condition  for  the  successful  manufacture  and  liberation 
of  plant  food  as  the  plants  need  it  and  the  ground  kept  in 
shape  so  that  it  will  always  be  relatively  cool  during  the 
growth  of  the  oat  plant,  one  does  not  have  to  worry 

about  the  cool  climate. 

• 

We  often  hear  that  an  oat  crop  should  be  planted  as 
early  in  the  spring  as  possible  and  that  an  early  frost 
clipping  the  green  plant  does  not  do  any  real  damage. 

The  real  reason  why  scientists  advocate  the  early 
planting  of  oats  is  on  account  of  the  cool  condition  of  the 
ground  necessary  for  the  development  of  this  plant. 

Plowing  for  oats  brings  up  an  interesting  question  and 
one  that  every  oat  grower  can  ponder  upon  with  profit. 

Is  it  necessary  to  plow  for  oats  or  can  the  ground  be 
disked  and  a  good  crop  grown? 

We  hear  diversified  opinions  as  to  the  results.  One 
year  farmers  maintain  that  plowing  increases  their 


70  THE  OLIVER  PLOW  BOOK 

crops  abundantly  and  another  year  they  contend  that 
disking  without  plowing  produces  a  better  crop.  Back 
of  it  all  is  this  one  fundamental  fact — the  ground  which 
was  in  the  proper  condition  for  the  growing  of  the  oats 
grew  the  best  crop. 

How  is  one  to  tell  whether  to  disk  or  plow  for  an  oats 
crop?  It  is  not  so  hard  if  one  stops  to  consider  two 
fundamental  facts.  The  first  is  that  moisture  keeps 
the  ground  from  readily  warming  in  the  early  spring; 
the  second,  it  keeps  the  ground  cool  in  the  hot  summer 
weather. 

The  seed  bed  must  be  made  so  as  to  warm  the  ground 
as  early  as  possible  in  the  spring  and  keep  it  cool  during 
the  warmer  weather.  To  do  this  naturally  means  that 
the  ground  must  be  put  in  condition  to  conserve  the 
water  and  prevent  the  ground  from  running  together  in 
a  plastic  condition  in  the  spring  of  the  year. 

•  If  the  winter  has  been  very  severe  and  the  ground  full 
of  frost,  this  condition  may  be  brought  about  by  merely 
disking  in  the  spring  because  freezing  expands  the  soil 
particles,  leaving  them  loose  after  thawing.  If,  on  the 
other  hand,  one  waits  until  spring  to  plow,  and  the 
spring  should  be  late,  he  may  be  losing  time  that  ought 
to  be  consumed  by  the  plants  in  growing  because  the 
plants  should  get  all  the  growth  they  possibly  can 
before  the  warmer  days  that  are  coming.  If  the  ground 
for  oats  is  left  cloddy,  half  pulverized,  it  cannot  grow  a 
good  crop  of  oats,  and  on  the  other  hand,  if  the  disking 
is  done  when  it  is  hard  below  the  surface  a  good  crop  of 
oats  cannot  be  grown  unless  Nature  is  very  propitious 
with  hard  rains  and  cool  weather,  but,  however  the  work 
is  done,  the  ground  must  be  in  the  proper  shape  for 


WHEN  TO  PLOW  71 


percolation  of  the  moisture  downward  in  the  spring,  and 
its  upward  trend  by  capillarity  later  in  the  season. 

These  two  illustrations  should  show  the  importance 
of  paying  the  closest  attention  to  plowing  at  the  right 
time.  The  same  laws  hold  true  of  any  crop. 


CHAPTER  VIII 


Plowing  to  Kill  Insects 

L3 LOWING  to  kill  insect  pests  is  a  most  important 
job  for  every  farmer.  It  is  the  ounce  of  prevention 
worth  the  pound  of  cure  in  the  pest  evil.  1 1  kills  insects  be- 
fore they  can  do  harm,  and  the  cost  is  nothing.  There  is  no 
farm  in  the  length  and  breadth  of  the  land  that  is  not 
some  time  or  other  afflicted  with  insect  pests  of  the  most 
ruinous  type.  One  must  not  expect  that  all  kinds  of 
insects  can  be  killed  with  the  plow.  Most  of  those 
which  commit  the  greatest  depredations  can  be  eradi- 
cated with  the  use  of  the  plow.  However,  before  one 
can  put  insect  pests  out  of  business  effectively  he  must 
know  and  understand  the  life  and  characteristics  of  the 
pests  just  exactly  as  he  must  know  the  life  and  character- 
istics of  plants  and  weeds. 

The  most  effective  methods  for  getting  rid  of  pests 
are  to  break  up  the  breeding  places,  starve  them  to 
death  and  make  impossible  the  hatching  of  insect  eggs. 
These  three  methods  can  be  successfully  worked  by  the 
use  of  the  plow  if  the  work  is  done  at  the  right  time 
and  the  ground  cultivated  to  keep  down  all  green  growth. 

It  is  generally  agreed  among  our  entomologists  that 
there  never  would  have  been  such  inroads  of  insect  pests 
in  the  field  had  it  been  plowed  at  the  right  time  of  the 
year  so  as  to  cover  the  trash  deep  in  the  furrow.  Leav- 
ing stubble,  such  as  grain,  corn  stalks,  cotton  stalks,  etc., 
on  the  surface  affords  the  most  propitious  protection  for 


PLOWING  TO  KILL  INSECTS  73 

insect  pests   that  feed  upon   these  plants.     Year  after 
year  they  continue  to  thrive. 

All  insect  pests  that  can  be  killed  with  plowing  pass 
the  winter  either  in  the  trash  on  the  surface  of  the 
ground  or  burrow  down  below  the  frost  line.  The  pests 
that  burrow  down  below  the  frost  line  are  usually  in  the 
larva  or  grub  state.  Those  that  stay  on  the  surface  in 
the  trash  are  mostly  full  grown  insects. 


The  stumpy  ground,  the  poor  covering  of  trash,  and  unevenly  plowed 
ground,  are  conditions  favorable  to  the  growth  of  insects. 

The  numberless  varieties  of  weevils  afflicting  the  south 
usually  pass  the  winter  without  food  in  the  rubbish  near 
their  feeding  ground.  They  start  hibernating  at  the 
first  frost  and  quickly  come  out  as  the  weather  warms 
and  then  they  return  as  it  cools.  Weevils  do  not  lie  in 
green  rubbish  nor  do  they  seem  to  possess  any  sort  of 
instinct  as  to  how  and  where  to  go  to  find  the  cotton  fields. 
Strong  winds  blow  them  many  miles.  Standing  stalks 
of  all  kinds  in  infested  fields  furnish  the  most  favorable 
conditions  for  the  hibernation  of  weevils.  Obviously  if 


74 


THE  OLIVER  PLOW  BOOK 


these  fields  are  plowed,  as  soon  as  possible  after  the  crop 
has  been  harvested,  deep  enough  so  that  the  stalks  will 
not  appear  above  the  ground  and  the  surface  of  the  field 
kept  clean  there  is  not  much  opportunity  for  a  weevil  to 
survive  in  that  place.  All  the  neighbors  doing  this  kind 
of  plowing,  cutting  down  weeds  and  grass  in  the  fence 
corners  and  burning  them,  seeing  to  it  that  the  trash 
and  surface  vegetation  near  the  cotton  fields  have  all 
been  burned,  aid  very  materially  in  reducing  the  boll 
weevil  pest. 

An  entirely  different  sort  of  plowing  is  necessary  to 
get  rid  of  the  white  grub.  The  white  grub  is  lazy,  that 
is  he  will  stay  on  the  surface  of  the  ground  as  long  as  he 


Contrast  this  field  and  plowing  with  that  shown  on  page  seventy -three. 
The  thorough  covering  of  cotton  stales  and  the  mellow  condition  of  the 
soil  mean  that  this  farmer  is  giving  his  crop  the  best  start  possible. 


PLOWING  TO  KILL  INSECTS  75 

can  and  gradually  work  his  way  downward  as  the 
weather  gets  cooler.  The  white  grub  lives  for  the  most 
part  in  timothy  meadows.  The  question  that  confronts 
the  farmer  is  whether  he  wants  to  use  the  meadow  for 
pasture  in  the  fall,  plow  the  ground  the  following  spring 
and  run  chances  of  having  the  grubs  destroy  his  corn,  or 
plow  to  get  the  grubs.  After  they  have  attained  their 
full  growth  they  are  nothing  more  or  less  than  the 
common  May  beetle  or  June  bug. 


These  four  white  grubs  were  found  in  a  square  foot  of  timothy  sod. 
When  anyone  learns  their  characteristics  it  is  a  comparatively  easy 
matter  to  keep  them  from  doing  a  great  amount  of  harm. 

The  time  to  plow  to  thoroughly  get  rid  of  white  grubs 
is  when  the  grubs  begin  to  bury  themselves  in  the 
ground.  Plowing  the  ground  at  that  period  and  turning 
all  the  hogs,  chickens  and  turkeys  into  the  field  to  feast 
on  these  grubs  will  rapidly  diminish  their  number.  If 
the  plowing  is  done  late  enough  frost  helps  in  the  killing. 

The  proper  remedy  for  getting  rid  of  the  Hessian  fly 
is  first  to  plow  immediately  after  harvest,  burying  the 
stubble  as  deep  in  the  ground  as  possible  and  to  keep 
the  surface  of  the  ground  well  cultivated  so  as  to  elimi- 


76  THE  OLIVER  PLOW  BOOK 

nate  lumps  and  clods  to  produce  a  finely  compacted  and 
moisture  conservation  seed  bed.  This  process  destroys 
all  volunteer  plants  which  may  grow  and  furnish  a 
means  for  propogating  the  fly.  The  principal  step  in 
this  process  is  to  plow  deep  and  cover  all  the  trash. 


The  crooked  furrow,  if  the  ground  is  trashy,  is  propitious  for  insect 
breeding.  It  is  impossible  to  always  plow  the  proper  width  of  cut  and 
as  a  result  the  furrows  are  not  laid  properly  to  cover  the  trash,  and  keep 
the  ground  from  drying  out  rapidly.  Trash  and  air  vents  in  the  ground 
are  good  incubators  for  insect  eggs.  The  two  combined  keep  out  moisture, 
the  greatest  hinder ance  to  insect  eggs  hatching. 


Cutworms,  like  white  grubs,  live  in  soil  that  has  been 
in  grass  for  a  number  of  years.  Meadows  infested  with 
cutworms  should  be  plowed  early  the  previous  fall.  The 
earlier  in  the  fall  the  ground  is  plowed  the  less  probability 
that  the  cutworm  moths  will  have  laid  their  eggs,  con- 
sequently the  injury  from  cutworms  the  following  year 
will  be  diminished.  Late  fall  and  winter  plowing  is  not 
so  effective  as  early  fall  plowing  for  the  eradication  of 
the  cutworm. 


PLOWING  TO  KILL  INSECTS  77 

Land  infested  with  billbugs  should  always  be  plowed 
in  the  late  summer  or  early  fall.  Plowing  at  this  time 
breaks  up  the  winter  lodging  of  the  bugs.  A  study  of 
the  life  of  billbugs  shows  that  they  also  live  on  many 
different  types  of  grasses.  Therefore,  it  is  necessary  for 
the  eradication  of  the  billbugs  to  plow  infested  grass 
fields  lying  next  to  the  other  ground. 

These  instances  are  citations  to  show  the  necessity  for 
studying  the  habits  and  f  characteristics  of  insect  life 
before  one  can  successfully  combat  it  with  the  use  of 
the  plow.  The  loss  that  is  sustained  by  farmers  on 
account  of  the  destruction  of  such  bugs  as  the  boll 
weevil,  white  grub,  wireworm,  grasshopper,  Hessian  fly, 
cutworm,  army  worm,  etc.,  is  estimated  by  some  authori- 
ties in  excess  of  five  billion  dollars  annually. 

To  kill  some  of  these  insects  it  is  necessary  to  plow  the 
ground  while  other  very  important  tasks  occupy  the 
attention  of  the  farmer.  The  necessity  for  a  means  to 
do  this  work  at  the  proper  time  arises.  The  solution  of 
the  problem  lies  in  the  means  the  farmer  has  in  his  hands 
for  doing  this  work  when  the  time  comes. 

A  great  deal  has  been  said  about  crop  rotation  for  the 
control  of  insect  pests.  All  this  is  good  but  the  first 
thing  in  the  eradication  of  bugs  of  any  kind  whatsoever 
is  to  plow  the  ground  thoroughly,  seeing  to  it  that  all 
trash  is  buried  deep,  leaving  none  on  the  surface.  Of 
all  types  of  insects  that  can  be  eradicated  by  plowing  it 
is  far  better  to  turn  the  stubble  under  immediately  after 
the  crop  has  been  harvested  than  to  burn  it.  All  of  this 
trash  represents  a  vast  amount  of  fertility  that  has  been 
taken  from  the  soil,  and  is  much  better  for  the  ground 
if  it  can  be  put  back  as  humus.  The  best  and  most 


78 


THE  OLIVER  PLOW  BOOK 


Cultivating  orchards  helps  to  faeef>  the  farm  rid  of  many  bad  insect 
pests  that  hibernate  in  such  places  during  the  winter  as  well  as  keeping 
the  weeds  and  grass  from  consuming  plant  food  that  should  be  utilized 
by  the  trees  in  developing  good  fruit.  When  we  learn  to  keep  weeds 
down  and  trash  burned  on  all  parts  of  the  farm  our  insect  troubles  will 
begin  to  disappear. 

effective  time  to  bury  trash  for  the  eradication  of  bugs 
is  when  it  produces  the  best  humus. 

Dry  vegetation  buried  in  the  ground  is  harder  to  rot 
than  green.  The  rotting  of  this  vegetation  helps  along 
in  the  destruction  of  insect  eggs  so  that  the  work  is  com- 
plete. It  is  a  self-evident  fact  that  if  there  is  enough 
fertility  and  the  soil  particles  are  arranged  so  that 
fermentation  is  taking  place  in  all  parts  of  the  seed  bed 
it  is  impossible  for  insect  eggs  to  hatch,  hence  the 
desirability  of  plowing  under  this  vegetation  while  it  is 
in  a  gieen  state. 


CHAPTER  IX 


Plowing  to  Kill  Weeds 

WEEDS,  like  the  proverbial  poor  relations,  are  always 
with  us,  and  they  always  will  be.  The  damage  done 
by  weeds  is  roughly  estimated  at  one  billion  dollars  per 
year.  It  can  be  easily  diminished  to  a  very  small  sum 
if  proper  precautions  are  taken.  One  must  study  the 
habits  and  characteristics  of  weeds  for  their  destruction 
in  the  same  way  that  he  must  study  the  habits  and 
characteristics  of  the  plant  that  he  desires  to  grow. 
Nature  acts  upon  the  principle  of  the  survival  of  the 
fittest.  Therefore,  the  farmer  must  till  his  land  to 
bring  about  a  condition  that  gives  the  crop  he  intends 
to  grow  the  advantage.  He  can  hardly  expect  to  do 
this  unless  he  understands  the  characteristics  of  both. 

It  would  require  an  immense  volume  to  treat  the 
peculiarities  and  habits  of  all  weeds  and  how  they  can 
be  eradicated,  and  if  a  volume  were  written,  in  six  weeks 
it  would  not  be  complete  because  Nature  is  constantly 
bringing  forth  new  varieties  of  weeds  with  considerable 
less  gusto  than  man  produces  new  varieties  of  grains. 
For  this  reason  farmers  must  not  always  expect  to  find 
the  answers  to  their  queries  written  in  a  book.  Indeed, 
they  will  seldom  be  found  there  because  climatic  con- 
ditions have  just  as  much  effect  upon  weeds  as  they  have 
upon  legitimate  plants.  Nature  does  not  distinguish 
between  the  two.  The  distinguishing  is  done  by  people 
whose  existence  depends  upon  the  food  qualities  of  the 
plants  they  desire  to  cultivate. 


80  THE  OLIVER  PLOW  BOOK 

A  most  vital  reason  why  one  should  understand  the 
characteristics  of  weeds  before  attempting  to  eradicate 
them  is  because  plowing  has  a  tendency  to  cultivate 
certain  types  of  weeds  rather  than  kill  them.  Sorrel 
and  quack  grass  are  two  very  common  examples  of  this 
type.  All  types  of  weeds  that  put  forth  a  new  sprout 
from  any  root  joint  can  be  eradicated  by  plowing  if  the 
ground  plowed  has  the  benefit  of  after  treatment  that 
will  keep  the  stems  from  becoming  exposed  to  the  sun- 
light. The  reason  is  the  stems  receive  their  nourish- 
ment from  the  leaves  which  are  exposed  to  the  sunlight. 
If  it  is  possible  to  keep  the  top  growth  down  so  the  leaves 
cannot  absorb  the  necessary  light  for  sustenance  the 
plant  naturally  starves  to  death. 

Those  surface  root  weeds  which  can  be  quickly  killed 
by  cutting  or  burying  in  the  ground  do  not  cause  much 
worry. 

The  three  great  rules  to  observe  are  first,  prevent 
weeds  from  going  to  seed;  second,  prevent  weed  seeds 
from  being  sown  on  the  farm;  and  third,  prevent  all 
weeds  from  making  a  top  growth. 

Farmers  must  not  expect  to  keep  their  weeds  down  in 
the  field  when  they  permit  them  to  grow  in  fence  corners, 
along  road  sides,  in  pastures  and  other  uncultivated 
fields  because  these  seeds  are  carried  by  the  wind,  birds, 
water,  and  animals  to  all  parts  of  the  field  where  they 
are  ready  for  a  new  start  and  in  very  favorable  condition 
for  germination  and  growth. 

Our  scientists  tell  us  that  annual  weeds,  those  which 
grow  from  the  seed  each  year,  may  be  eradicated  by  any 
method  which  starts  germination  and  then  destroys  the 
plant  before  it  produces  seed.  Biennial  weeds,  or  those 
that  live  two  years  between  the  germinating  of  the  seed 
and  the  maturity  of  the  plant,  require  an  entirely  dif- 


PLOWING  TO  KILL  WEEDS 


81 


A  field  plowed  in  July  so  as  to  completely  bury  the  weeds  in  a  corner 
of  the  furrow.     Wheat  was  planted  in  the  fall. 


The  following  year  this  wheat  crop  was  harvested  without  any  of  the 
weeds  turned  under  the  precious  fall  appearing  in  this  stubble. 


82 


THE  OLIVER  PLOW  BOOK 


Result  of  a  portion  of  a  field  plowed  with  the  combined  rolling  coulter 
and  jointer  attached  to  the  plow. 

ferent  treatment.  The  habit  of  cutting  the  tops  of 
these  plants  is  not  always  the  most  desirable  method 
because  very  many  of  them  will  put  out  new  leaves  and 
produce  seeds,  consequently,  if  the  cutting  method  is 
practiced  the  tops  must  be  cut  sufficient  times  during  the 
season  to  prevent  the  plants  going  to  seed.  Perennial 
weeds,  or  those  that  grow  from  the  roots,  are  the  most 
difficult  to  handle.  A  method  of  cultivation  that  will 
expose  the  roots  to  the  surface,  and  prevent  them  start- 
ing growth  is  the  most  successful. 

In  all  these  different  types  of  weeds  one  striking  fact 
stands  out.  That  is  both  weed  and  legitimate  plants 
require  the  gases  from  the  air  which  must  come  in 
through  the  leaves  and  stem.  This  being  true  the  first 
course  in  the  destruction  of  weeds  is  to  prevent  this  food 


PLOWING  TO  KILL  WEEDS 


83 


A  portion  of  the  field  shown  on  page  eighfy-two  plowed  with  the  same 
plow  without  the  combined  rolling  coulter  and  jointer.  These  tall 
weeds  were  thick  all  offer  the  field  when  the  ground  was  plowed  prepar- 
atory to  growing  this  crop. 

assimilating  process.  It  is  a  difficult  task  to  attempt  to 
do  this  work  by  hand  in  large  fields.  The  work  must  be 
done  with  tillage  implements.. 

The  first  step  is  to  fall  plow  as  deeply  as  it  is  possible 
for  the  plow  to  operate.  The  deeper  the  weed  seeds  are 
turned  under  the  better.  Every  leaf,  stem,  and  all  the 
seeds  must  be  turned  to  the  bottom  of  the  furrow.  For 
this  reason  it  is  unwise  to  disk  such  ground  in  the  fall 
before  plowing  it.  Experiments  have  been  tried  which 
proved  beyond  a  question  of  a  doubt  that  the  action  of 
the  disk  harrow  in  ground  of  this  kind  has  a  tendency  to 
sow  the  seed  rather  than  eradicate  it,  while  leaving  the 
surface  of  the  ground  unmolested  and  turning  all  surface 
trash  completely  under  with  a  plow  has  rid  a  field  of  all 
classes  of  weeds. 


84 


THE  OLIVER  PLOW  BOOK 


A  field  of  tall  weeds  being  turned  under  with  a  plow  having  a  com- 
bined rolling  coulter  and  jointer  attached. 

The  combined  rolling  coulter  and  jointer  for  this  work 
is  the  most  valuable  addition  to  the  plow.  This  device 
turns  all  the  surface  trash  and  weeds  into  the  lower 
*  right-hand  corner  of  the  furrow.  Turning  them  under 
deep  in  this  manner  means  that  the  new  shoots  which 
the  seed  will  send  forth  take  additional  strength  and 
nourishment  from  the  root  system  before  they  can  reach 
the  surface.  This  growth  impoverishes  the  root,  thus 
the  growth  is  retarded  and  the  weeds'  vitality  weakened. 

If  the  plowing  has  been  done  at  the  right  time  in  the 
fall  the  winter's  freezing  will  come  along  and  kill  the 
tender  plants.  If  the  weeds  are  of  a  variety  that  will 
come  up  very  soon  after  plowing,  the  infested  field 
should  be  plowed  early  in  the  fall  and  when  the  weeds 
come  to  the  surface  and  begin  developing  leaves,  surface 
cultivating  of  the  ground  with  the  weeder  or  disk  harrow 


PLOWING  TO  KILL  WEEDS 


85 


77ie  identical  spot  in  the  picture  shown  on  page  eighty-four  taken  the 
following  year.  This  field  had  no  hand  cultivation,  simply  that  of  a 
one-row  horse  cultivator.  None  of  the  varieties  of  weeds  turned  under 
appeared  in  this  field. 

will  immediately  destroy  the  weeds.  The  great  trouble 
with  unsuccessful  practices  of  this  kind  has  been  the 
failure  to  carry  the  after  work  through  carefully  enough 
to  kill  all  sprouting  weeds.  Quack  grass  has  been  suc- 
cessfully eradicated  by  this  method  but  the  operator 
did  not  permit  a  single  leaf  or  stem  to  develop.  In  one 
instance  the  farmer,  after  plowing,  kept  up  this  cultiva- 
ting operation  from  spring  until  fall.  He  wanted  to 
plant  corn  on  that  field  but  his  greater  ambition  was  to 
kill  the  quack  grass,  so  he  kept  cultivating  until  fall  and 
sowed  the  field  to  fall  wheat,  reaping  a  much  better  crop 
than  he  would  have  had  he  planted  corn,  and  he  entirely 
rid  the  field  of  quack  grass. 

The  secret  of  his  success  lay  in  the  fact  that  he  kept  the 
stems  and  leaves  from  drinking  in  the  sunlight  to  sustain 
the  roots.  The  result  was  the  root  system  started  to 
rot  as  it  will  do  with  all  weeds  just  exactly  as  it  does 
with  other  plants. 


86 


THE  OLIVER  PLOW  BOOK 


Sectional  view  showing  weeds  buried  in  the  lower  corner  of  the 
furrow  deep  enough  to  prevent  their  getting  a  good  growth  in  the  fall 
before  the  winter's  freezing  will  fall  them.  If  the  same  plowing  were 
done  in  the  spring  the  crops  planted  above  would  sprout  and  grow  before 
the  weeds  could  get  a  start. 

In  this  weed  killing  process  a  farmer  may  often  be 
obliged  to  choose  between  the  loss  of  his  ground  for  a 
year  or  the  growth  of  such  a  crop  as  he  can  expect  to 
raise  in  a  weedy  field. 


*This  reference  means  when  right-hand  plows  are  used.     When  left-hand  plows 
are  used  the  weeds  should  be  in  the  lower  left-hand  corner. 


CHAPTER  X 


Plowing  Under  Green  Manure 

ONE  is  often  troubled  as  to  the  proper  time  to  plow 
under  a  green  manure  crop.       The  answer  centers 
around  the  quickness  with  which  a  crop  is  desired. 

It  is  common  knowledge  that  a  green  plant  turned 
under  will  rot  quicker  than  one  that  has  reached  maturi- 
ty, and  is  in  a  dry  condition  when  plowed.  Evidently 
then,  the  time,  if  quick  results  are  desired,  is  to  plow 
when  the  crop  is  in  a  green  state. 

Scientists  tell  us  that  the  best  time  to  plow  under  a 
green  crop,  if  it  is  clover  or  some  other  legume,  is  just 
before  the  blossom  shows  signs  of  turning.  The  reason 
is  the  stems  and  leaves  are  in  the  green,  or  sugar  state 
and  contain  more  of  the  plant  food  elements  than  the 
crop  that  has  not  reached  this  period  of  growth.  Plow- 
ing under  a  green  crop  any  later  than  this  means  that 
the  plant  has  reached  a  fibrous  and  starchy  condition 
and  is  much  harder  for  moisture  to  dissolve.  Obviously 
more  time  will  be  required  to  reach  a  state  when  fer- 
mentation can  set  in. 

The  clover  plant  moves  much  of  the  sugar  from  the 
leaves  and  stems  into  the  roots  and  stores  it  there  in  the 
form  of  starch  for  the  winter.  In  this  condition  clover 
is  more  resistant  to  decay,  consequently,  when  plowed 
late  in  the  fall  there  may  not  be  enough  time  for  the 
plant  to  decay  before  the  crop  is  planted.  For  this 
reason  it  is  always  advisable  to  plow  clover  under  in 


88  THE  OLIVER  PLOW  BOOK 

the  green  state.  Regardless  of  the  time  of  the  year  that 
plowing  is  done,  decomposition  will  proceed  faster  if  the 
matter  plowed  under  is  always  green.  Hence,  the  ideal 
time  for  plowing  under  a  crop  of  green  manure  would  be 
to  do  the  plowing  at  a  time  of  the  year  when  the  crop  is 
green. 

If  the  location  is  such  that  there  is  a  scant  supply  of 
rainfall  a  heavy  green  manure  crop  plowed  under  after 
it  reaches  the  starchy  stage  can  ruin  the  following  crop. 
It  has  been  known  to  do  so  in  a  great  many  cases  al- 
though it  is  a  question  whether  the  farmer,  whose  crops 
were  ruined,  understood  the  reason  for  it. 

To  cut  a  heavy  crop  and  leave  it  lying  loose  on  the 
ground  before  turning  it  under  loses  an  immense  amount 
of  organic  matter.  The  principal  object  of  plowing 
under  green  manure  is  to  put  organic  matter  into  the 
soil,  hence  there  is  nothing  gained  by  plowing  under 
vegetation  if  it  is  mowed  and  left  standing  on  the  field. 
It  is  far  better  to  plow  under  the  green  crop  without 
cutting  it.  In  this  way  all  the  organic  matter  is  placed 
in  the  soil  in  the  proper  condition. 

Spring  plowing  of  rye  sown  in  the  early  previous  fall 
is  apt  to  cause  trouble  in  the  clay  soils  if  the  field  is 
pastured  in  the  early  spring  and  the  ground  happens  to 
be  wet  and  later  on  when  desiring  to  plow,  the  weather 
turns  off  dry,  because  the  ground  is  packed  hard  and 
will  not  break  into  a  friable  condition.  If  rye  is  per- 
mitted to  grow  until  late  in  the  spring  and  then  plowed 
under  it  is  very  likely  to  break  up  capillary  connection 
with  the  sub-surface  and  keep  the  ground  so  that  it  will 
interfere  very  seriously  with  the  crop  from  feeding  on 
what  nourishment  already  is  in  the  ground. 


PLOWING  UNDER  GREEN  MANURE  89 

A  problem  arises  when  plowing  stubble  with  the  idea 
of  making  fertilizer  out  of  it  when  the  ground  is  so  dry 
and  hard  that  there  is  little  opportunity  for  enough 
moisture  to  come  up  from  below  to  rot  the  stubble 
turned  under.  Since  moisture  is  the  only  means  to  rot 
this  turned  over  stubble  it  is  absolutely  necessary  to 
bring  about  a  condition  in  the  ground  whereby  moisture 
can  come  up  from  below.  Obviously  then,  plowing 
should  be  done  to  see  that  the  trash  is  buried  as  deeply 
as  possible  on  the  bottom  of  the  furrow  in  such  a  way  as 
to  interfere  as  little  as  possible  with  the  upward  trend  of 
moisture. 

Fertilizer  crops  of  all  kinds  must  always  be  plowed 
under  with  the  idea  of  their  becoming  well  rotted  and 
decayed  before  the  crop  is  planted. 

If  the  soil  which  the  farmer  desires  to  turn  under  is  of 
a  loose,  ashy-like  composition  and  the  rolling  coulter 
will  not  cut  through  the  .vegetation,  a  condition  is  met 
which  is  exceedingly  difficult  to  handle. 

Soil  of  this  kind  is  always  lacking  in  humus.  The 
time  that  one  usually  desires  to  plow  these  fields  is  when 
they  are  dry  and  in  the  ashy  condition.  If  a  strict 
watch  is  kept  upon  the  rainfall,  and  the  ground  should 
be  moist  at  the  plowing  depth  during  the  growing  period 
of  the  cover  crop,  the  ground  can  be  plowed  when  the 
moisture  is  sufficient  to  hold  the  soil  together.  Every 
man  is  the  best  judge  of  his  own  farm  in  this  respect. 

The  reason  for  the  ground  being  in  the  dry  and  ashy 
condition  is  its  lack  of  organic  matter  or  humus. 

The  purpose  of  growing  the  green  manure  crop  is  to 
put  this  organic  matter  into  the  soil.  If  the  plowing  is 
improperly  done  and  the  crop  poorly  plowed  under  the 


90 


THE  OLIVER  PLOW  BOOK 


Burying  fertilizer  at  this  depth,  ten  inches  in  the  ground,  will  do  a 
grain  crop  planted  on  the  surface  little  or  no  good.  Buried  in  this  manner 
manure  will  not  stop  the  upward  trend  of  moisture  to  any  extent  but  if  it 
were  scattered  across  the  furrow  bottom  as  is  usually  done  the  upward 
trend  of  moisture  would  be  stopped  sufficiently  to  ruin  a  crop  in  a  dry  year. 

greatest  good  cannot  be  secured  from  the  cover  crop. 
This  ashy  condition  cannot  exist  if  the  soil  contains  a 
great  quantity  of  organic  matter,  hence  the  very  purpose 


PLOWING  UNDER  GREEN  MANURE  91 

plowing  under  green  clover  is  to  accomplish  is  defeated 
unless  it  is  thoroughly  covered  when  plowing. 

The  principal  reason  why  farmers  mow  green  crops 
before  plowing  them  under  is  because  of  their  inability 
to  successfully  cover  them  with  the  plow.  With  the  advent 
of  the  combined  rolling  coulter  and  jointer  this  difficulty 
is  overcome.  This  attachment  on  a  plow  will  turn 
under  the  rankest  growth  of  green  vegetation  more 
efficiently  than  dry  vegetation  can  be  turned  under  in 
the  ordinary  manner. 


CHAPTER  XI 


Judging  Plowing 

WHEN  one  considers  that  different  soils  must  be 
plowed  in  a  manner  to  accomplish  the  desired 
results,  it  becomes  self-evident  that  it  is  impossible  to 
lay  down  a  certain  set  of  laws  or  rules  to  determine  what 
constitutes  prize  plowing.  The  most  beautiful  job  of 
plowing  on  the  surface  is  not  proof  that  the  ground 
will  grow  the  best  crop. 

Before  a  perfect  job  of  plowing  can  be  done  the  fol- 
lowing requirements  must  be  fully  met. 

Each  furrow  must  be  straight  from  end  to  end. 

Back  furrow  must  be  slightly  raised  and  all  trash 
covered. 

The  top  lines  of  the  furrows  must  be  uniform  without 
breaks  or  depressions.  The  top  of  the  furrow  may  be 
slightly  ridged.  Ground  must  be  thoroughly  pulver- 
ized from  the  top  to  the  bottom  of  the  furrow;  no  air 
spaces  anywhere  in  the  furrow  slices. 

Trash  must  not  be  visible  in  the  line  of  furrow  and 
should  be  buried  in  the  lower  right-hand  corner  of  the 
furrow. 

Furrows  must  be  uniform  compared  one  with  another. 

The  depth  of  all  furrows  must  be  the  same  and  con- 
tinue a  uniform  depth. 

Dead  furrows  must  be  free  from  unturned  ground. 

The  above  rules  are  recognized  as  the  standard  by 
which  plow  contests  are  judged.  It  is  obvious  that 


JUDGING  PLOWING 


93 


This  picture  of  fall  plowing  and  the  two  following  were  taken  in  the 
same  field,  on  the  same  day,  the  different  appearances  of  the  soil  being 
caused  by  the  curvature  of  the  mouldboards  of  the  plows  doing  the  work- 
The  soil  was  a  clay  loam.  If  the  ground  were  to  be  left  as  plowed 
through  the  winter  it  is  obvious  that  this  kind  of  plowing  would  be 
better  than  either  of  the  other  two  because  being  rough  it  would  not 
run  together  and  become  compacted  by  the  spring  thaws  and  rains. 


This  field  can  be  easier  worked  into  a  seed  bed  than  that  shown  above 
but  not  so  easily  as  that  shown  on  page  ninety-four,  hence  it  would  not  be 
regarded  so  good  plowing  for  spring  planting  or  immediate  seeding  as 
the  other  two. 


94  THE  OLIVER  PLOW  BOOK 


//  this  ground  is  to  be  seeded  immediately  it  is  plainly  apparent  that 
it  can  be  worked  into  an  ideal  seed  bed  much  quicker  than  the  two  fields 
shown  on  page  ninety-three.  However,  if  this  ground  is  to  be  left  for 
spring  planting  and  the  locality  happens  to  be  one  where  there  is  a  great 
deal  of  snow  and  rainfall,  the  ground  may  have  to  be  replowed  on 
account  of  the  extreme  mellowness  making  it  apt  to  run  together. 

plowing  to  fulfill  these  requirements  would  not  be  so 
good  for  crop  growing  in  some  sections  as  another  type 
of  plowing  that  would  far  from  fill  these  requirements. 
Hence,  it  would  be  much  better  for  those  who  are 
deciding  plowing  contests  to  judge  the  quality  of  work 
in  accord  with  the  results  expected  of  the  plowing. 

Plowing  being  done  primarily  for  growing  crops  it 
would  seem  logical  that  the  rules  of  plowing  contests 
should  be  worded  so  as  to  promote  the  kind  of  plowing 
that  will  produce  the  best  crops  on  the  ground  being 
plowed.  Sod  plowing  should  not  be  judged  as  stubble 
plowing;  plowing  for  wheat  should  not  be  judged  the 
same  as  plowing  for  corn,  etc. 

The  second  rule,  back  furrow  slightly  raised  and  all 
trash  covered,  is  a  good  one  to  follow  in  clay  and  loam 
soils.  It  is  easy  to  understand  how  these  requirements 


JUDGING  PLOWING 


This  picture  shows  a  job  of  plowing  in  a  sandy  loam  soil.  The 
furrows  are  even  in  width  and  depth  and  laid  to  make  an  evenly  plowed 
field.  The  back,  furrow  is  not  raised  enough  so  that  it  can  be  detected 
from  the  other  furrows. 


This  plowing  won  the  first  prize  at  a  plowing  contest.  The  soil  was 
of  an  exceedingly  clayey  nature,  entirely  different  from  the  soil  in  the 
field  illustrated  above,  yet  the  plowing  is  very  similar.  The  field  shown 
above  Was  plowed  in  the  spring,  while  this  field  was  plowed  in  the  fall. 


would  utterly  fail  in  plowing  sandy  soils  on  account  of 
their  loose  construction.  As  a  matter  of  fact,  the  leveler 
sandy  soils  are  left  on  the  surface,  providing  the  surface 


96  THE  OLIVER  PLOW  BOOK 

is  loose,  the  less  moisture  escapes  from  them.  Hence, 
from  a  practical  standpoint  the  plow  bottom  that  leaves 
sandy  soils  level  after  plowing  is  better  for  the  soil  than 
one  that  leaves  it  ridged  or  crowned. 

A  much  better  way  to  judge  plowing  is  to  take  a  spade 
or  some  other  sharp  cutting  instrument  into  the  field 
and  see  what  is  happening  at  the  bottom  of  the  furrow. 
If  there  are  large  air  spaces  and  clods  the  plowing  is 
certainly  poor  from  a  crop  producing  standpoint.  If  the 
bottom  of  the  furrow  is  covered  with  trash  so  that  the 
upward  trend  of  capillarity  is  interfered  with  it  is  also 
equally  bad  plowing. 

Plowing  is  good  when  the  furrow  slice  is  well  pulver- 
ized from  top  to  bottom,  large  air  spaces  eliminated, 
and  the  trash  buried  to  interfere  as  little  as  possible 
with  the  upward  trend  of  moisture. 


CHAPTER  XII 

Plow  Bottoms 

PHE  bottom  is  the  business  end  of  the  plow.  Upon 
•1  its  performance  depends  the  quality  of  the  seed  bed 
the  farmer  can  prepare.  Since  the  quality  of  the  seed  bed 
determines  very  largely  the  start  a  crop  gets  it  is  obvious 
that  a  plow  bottom  is  the  vital  part  of  a  farmer's  equip- 
ment. All  the  rest  of  the  plow  is  merely  for  the  purpose 
of  enabling  the  operator  to  make  the  bottom  work 
correctly. 

When  one  reflects  upon  what  has  been  said  in 
Chapter  V  about  different  soil  compositions,  the 
effect  of  humus,  lack  of  humus,  fertility,  moisture,  air 
and  heat  upon  plant  growth  the  reason  why  one  must 
use  a  plow  bottom  adapted  to  that  particular  kind  of 
soil  becomes  plain. 

Manufacturers  have  not  yet  been  able  to  make  any 
one  bottom  that  can  be  adapted  to  all  these  different 
types  of  soil.  This  explains  why  farmers  who  have  sand 
and  clay  soils  should  have  both  chilled  and  steel  bottoms 

with  entirely  different  shaped  mouldboards. 

• 

Plow  builders  are  doing  their  utmost  to  design  bot- 
toms that  will  approach  the  best  work  in  all  conditions 
under  which  farmers  plow.  They  have  been  remarkably 
successful  in  building  bottoms  that  will  plow  excep- 
tionally well  in  all  types  of  soils  that  have  one  or  more 
common  characteristics  but  when  the  demarkation  is 
too  pronounced  it  is  necessary  to  change  the  shapes  of  the 
mouldboards  in  order  to  properly  stir  the  soil. 


98  THE  OLIVER  PLOW  BOOK 

A  knowledge  of  what  constitutes  good  plowing  is 
necessary  before  one  can  judge  whether  the  bottom  is 
particularly  adapted  to  that  soil.  It  does  not  matter 
what  type  of  soil  a  farmer  is  tilling,  the  conditions 
necessary  for  plant  growth  must  be  the  same.  The 
soil  must  be  well  pulverized  and  properly  compacted  so 
that  air  and  moisture  can  mingle  in  every  particle  and 
recess  at  all  times,  whether  the  soil  is  sand,  clay,  loam, 
muck,  or  any  other. 

It  is  reasonable  to  assume,  in  view  of  the  entirely 
different  characteristics  of  soil,  that  clay  would  be 
broken  into  clods  with  the  same  type  of  mouldboard 
which  successfully  pulverizes  sand. 

The  plow  bottom  is  nothing  more  or  less  than  a  three 
sided  wedge.  The  cutting  edge  of  the  share  and  landside 
are  flat  sides  of  the  wedge.  The  mouldboard  and  upper 
portion  of  the  share  are  curved  and  made  to  invert  the 
earth.  The  curvature  and  length  of  the  mouldboard 
have  to  do  with  the  pulverization  of  the  soil. 

The  bluffer  the  mouldboard  is  the  more  rapidly  it  will 
pick  up  the  earth  and  turn  it  over.  For  this  reason  all 
types  of  plow  bottoms  that  are  used  in  plowing  the 
looser  soils  are  naturally  bluffer  than  those  used  in 
plowing  soils  that  stick  together  such  as  clay.  It 
obviously  follows  from  thes"e  two  extremes  that  the 
types  of  mouldboards  used  for  plowing  loamy  soil  must 
lean  more  toward  the  bluff  as  sand  predominates  and 
toward  the  longer  curve  as  clay  predominates. 

There  are  countries  where  it  is  necessary  to  plow  clay 
soils  when  they  are  wet  because  of  excessive  rainfall  and 
no  frost.  This  calls  for  a  peculiarly  shaped  plow  bottom 
that  is  not  very  well  understood  in  other  sections  of  the 


PLOW  BOTTOMS  99 


world.  This  soil  is  nearly  always  of  a  waxy,  putty 
nature  and  holds  water  much  the  same  as  an  earthen 
basin.  For  this  reason  tiling  or  draining  has  never  been 
successful,  hence  a  plow  bottom  to  successfully  turn  this 
soil  must  turn  a  furrow  well  over,  yet  let  it  stand  on  a 
corner  of  the  furrow  slice  and  leave  small  crevices  or 
sub-surface  ditches  on  the  bottom  between  each  furrow. 
This  gives  excellent  drainage  so  that  the  sharp  top 
corner  of  the  furrow  can  soon  dry  and  crumble,  leaving 
a  few  inches  of  soil  on  the  surface  that  can  be  worked 
to  bring  about  the  condition  necessary  for  the  right 
mixture  of  air  and  moisture  for  plant  growth. 

Prairie  sod  is  full  of  grass  roots  and  decayed  vegeta- 
tion. This  ground  is  plowed  to  start  the  decaying  of 
grass  as  rapidly  as  possible.  The  ultimate  object  of 
such  plowing,  of  course,  is  to  put  the  ground  in  a  con- 
dition of  tilth  for  the  successful  growing  of  crops.  The 
rotting  of  the  grass  being  the  first  step  the  sod  should  be 
plowed  to  bring  this  about  in  the  quickest  possible  time. 
In  most  soils  the  complete  reversing  of  the  sod  is  sup- 
posed to  smother  the  stems  and  leaves  of  the  grass  so 
they  rot  and  decay  very  rapidly.  This  must  be  done 
in  a  way  to  prevent  new  stems  from  springing  up. 

The  success  of  this  process  depends  upon  plowing  the 
ground  at  a  season  of  the  year  when  there  is  moisture 
enough  to  start  rapid  decay  or  a  much  longer  time  than 
should  be  necessary  will  be  consumed  in  the  complete 
decomposition  of  the  sod.  The  discussion  on  capillary 
water  explains  why  this  is  necessary. 

The  thing  to  remember  is  that  regardless  of  the  kind 
of  grass  the  plant  must  be  prevented  from  putting  forth 
new  stems  and  leaves  which,  as  is  mentioned  in  a  pre- 
vious chapter,  all  plants  will  do  when  air  and  moisture  are 


100 


THE  OLIVER  PLOW  BOOK 


permitted  to  mingle  in  such  a  way  that  the  root  system 
can  put  forth  new  stems.  Hence,  the  ideal  system  for 
plowing  sod  is  to  see  that  all  portions  of  the  grass  plant 
are  completely  buried  and  the  ground  packed  as  closely 
around  these  leaves  as  it  is  possible  to  do  in  order  that 
sunlight  may  be  kept  away  from  the  turned  over  leaves. 

One  can  rest  assured  that  if  there  is  a  possible  ray  of 
sunlight  peeping  through  the  turned  furrow  where  the 
leaf  of  wild  and  native  prairie  grass  lies  the  blade  of 
grass  will  grow  through  that  hole,  hence  the  furrow  slice 
should  be  thick  enough  to  keep  out  sunlight  and  air. 
If  this  is  done  effectively  shallow  root  crops  such  as  flax 
can  be  planted  and  they  will  act  as  an  aid  in  the  final 
breaking  up  of  the  sod  structure. 


Illustration  E 


The  kind  of  plowing  the  bottom  illustrated  above  does.  Observe  the 
furrow  slice  is  laid  over  flat  to  keep  all  the  air  and  light  away  from  the 
leaves  and  stems  of  the  grass. 


PLOW  BOTTOMS  tbl 


Special  plows  are  required  for  this  purpose.  The 
shape  of  the  share  and  mouldboard  is  such  that  the 
furrow  is  turned  over  disturbing  its  composition  as 
little  as  possible.  Illustration  E  shows  this  type  of 
mouldboard. 

The  other  influencing  factor  in  reference  to  shapes  of 
mouldboards  is  sticky  soils  that  do  not  have  enough 
body  to  hold  together  to  give  the  amount  of  pressure 
necessary  to  force  the  dirt  off  the  mouldboard.  Natur- 
ally, in  designing  plows  for  work  in  this  type  of  soil  the 
mouldboards  and  shares  are  designed  to  crumble  the 
soil  as  little  as  possible.  The  curvature  is  less  pro- 
nounced than  in  any  other  type  of  plow  bottom. 

There  are  various  ways  of  explaining  the  crumbling 
and  crushing  influences  upon  the  earth  as  it  passes  over 
the  mouldboard,  but  a  very  simple  explanation  is  found 
in  observing  the  distance  that  the  top  and  bottom  of  the 
furrow  slice  travel  in  the  process  of  being  picked  up  and 
turned  over. 

It  is  obvious  that  the  bottom  of  the  furrow  slice 
travels  a  much  longer  distance  when  being  inverted  than 
the  top  or  stubble  side.  This  process  of  inverting  the 
furrow  means  breaking  up  the  earth  into  particles. 
Whether  these  particles  are  broken  into  larger  or 
smaller  clods  depends  upon  the  tenacity  with  which  they 
stick  together  andj^the  shape  of  the  mouldboard  for 
pulverizing. 

The  broad  principle  employed  in  shaping  the  curva- 
ture of  mouldboards  is  one  that  will  cause  the  soil 
granules  to  roll  one  upon  another  and  thus  break  their 
cohesion.  A  closely  textured  soil,  plowed  while  wet, 
increases  the  cohesions  of  the  granules  so  that  they  will 
not  fall  apart  in  the  act  of  plowing.  Thus  a  mouldboard 


102.    t%li     e  .^.THH.  OLIVER  PLOW  BOOK 

that  does  a  perfect  job  of  plowing  in  soil  that  is  in  the 
proper  condition  for  plowing  will  be  ruinous  to  this  soil 
when  plowing  it  too  wet. 

It  is  further  obvious  that  those  soils  which  must  be 
plowed  when  wet  require  the  use  of  a  mouldboard  that 
will  break  them  as  little  as  possible  while  being  turned. 
This  characteristic  identifies  those  types  of  plow  bot- 
toms used  for  plowing  wet  soils  that  do  not  have  the 
benefit  of  the  winter's  freezing. 

The  illustrations  of  the  following  plow  bottoms  will 
suffice  to  make  clear  the  efforts  being  put  forth  to  build 
bottoms  suitable  for  all  conditions. 


Illustration  F 


Illustration  F  shows  a  steel  base,  general  purpose 
bottom.  By  general  purpose  is  meant  a  plow  that  will 
not  only  plow  stubble,  but  also  tame  grass  sods.  The 
shape  of  this  bottom  is  such  that  it  scours  in  a  great 
many  varieties  of  soils.  This  bottom  turns  a  furrow 
well  over  and  leaves  an  even,  well  crowned  furrow  top. 
The  types  of  soil  in  which  this  bottom  gives  the  best 
satisfaction  are  the  sandy  and  clay  loam,  and  some  waxy 
soils  where  scouring  is  a  hard  problem.  This  plow 
bottom  is  well  adapted  to  heavy  loam  and  gumbo  soils, 


PLOW  BOTTOMS 


103 


This  ground  was  plowed  with  a  bottom  li^e  the  one  shown  in  illustra- 
tion F.  The  characteristics  of  this  bottom  are  plainly  discernible  in  the 
plowed  ground. 


provided  the  ground  is  not  wet,  or  does  not  disintegrate 
or  slack  when  it  comes  in  contact  with  air.  Whenever 
plowing  ground  where  the  furrow  slices  do  not  hold 
together  well  this  shaped  bottom  can  be  safely  used. 
On  account  of  the  shape  and  gradual  turn  of  the  mould- 
board  it  does  an  exceptional  job  of  pulverizing. 


Illustration  G 


Illustration  G  is  a  long,  slow  turn  bottom  particularly 
adapted  to  stiff  clay  soils  and  all  classes  of  soils  that 


104 


THE  OLWER  PLOW  BOOK 


°f  the  plow  bottom  shown  in  illustration  G.  Observe  that  the 
ground  is  very  finely  pulverized  and  the  few  clods  are  flat.  The  surface 
of  the  ground  is  level;  furrow  crowning  is  imperceptible.  The  furrow 
bant^  is  smooth,  the  bottom  is  well  cleaned,  leaving  an  ideal  surface  for 
the  following  bottom  to  lay  the  next  furrow  slice. 


have  clay  in  their  composition.  This  bottom  thoroughly 
pulverizes  clay  if  the  soil  is  in  a  condition  to  be  plowed. 
The  shape  of  this  mouldboard  is  such  as  to  cause  the 
earth  to  separate  in  layers  rather  than  to  break  into 
lumps.  It  is  distinctly  noticeable  in  a  field  plowed  with 
this  bottom  that  the  few  clods  left  are  always  flat  shaped 
and  very  frequently  will  fall  into  pieces  when  picked  up. 
Naturally,  a  bottom  that  does  this  kind  of  work  requires 
more  power  than  one  which  does  not  pulverize  the 
ground  as  effectively. 


PLOW  BOTTOMS 


105 


Illustration  H 

Illustration  H  is  a  general  purpose  bottom  made 
specifically  for  work  in  all  types  of  clay  and  sandy  loam 
that  are  hard  to  penetrate.  It  is  also  the  most  desirable 
bottom  for  use  in  these  same  types  of  soil  full  of 
gravel,  cobblestones  and  shale  or  flat  stone.  This 
bottom  is  made  with  a  narrow  breast  which  permits  the 


of  the  plow  bottom  as  shown  in  illustration  H.  In  view  of 
the  fact  that  it  is  necessary  to  aerate  soils  when  they  are  being  plowed  a 
plow  bottom  to  work  in  this  type  of  soil  must  be  designed  to  prevent  stones 
from  throwing  it  out  of  the  ground  the  least  number  of  times  and  when 
it  is  thrown  out  to  penetrate  quickly-  This  type  of  bottom  does  this  work 
exceptionally  well. 


106 


THE  OLIVER  PLOW  BOOK 


use  of  a  strong  and  well  tapered  share  required  for  stony 
lands,  consequently  this  bottom  will  penetrate  this  kind 
of  ground  and  thoroughly  stir  it  which  is  necessary  if  the 
oxygen  in  the  air  is  to  mix  freely  in  the  ground.  This 
kind  of  plowing  cannot  be  accomplished  in  these  soils 
with  an  ordinary  bottom.  The  narrow  breast  and  the 
high  delivery  mouldboard  insure  the  earth  being  well 
mixed  in  the  process  of  plowing. 


Illustration  I 


Illustration  I  is  a  general  purpose  bottom.     This  bot- 
tom is  made  to  plow  the  volcanic  ash  soils  that  are  found 


The  work  of  the  plow  bottom  shown  in  illustration  I.     Observe  the 
deep  furrow  wall  and  the  well  turned  furrow  slices. 


PLOW  BOTTOMS  107 


in  the  northwestern  section  of  the  United  States.  In 
plowing  these  peculiar  types  of  soils  the  farmer  fre- 
quently desires  to  plow  deep.  This  can  be  accomplished 
with  this  bottom.  The  shape  of  the  mouldboard  is 
curved  so  as  to  pulverize  this  type  of  soil  exceptionally 
well. 


Illustration  J 


The  slat  mouldboard  gives  less  surface,  hence  less  earth  sticks.     For 
this  reason  the  slat  bottom  serves  a  good  purpose. 


Illustration  J  shows  a  slat  bottom.  There  are  soils 
so  sticky  by  nature  that  the  ordinary  plow  bottom  will 
not  scour.  These  soils  will  not  hold  together  sufficiently 
to  give  enough  pressure  against  the  mouldboard  for 
scouring.  The  slat  bottom  eliminates  a  part  of  the 
mouldboard.  Therefore,  there  is  not  so  much  surface 
to  which  the  earth  may  stick.  For  this  reason  a  slat 
bottom  will  scour  and  do  a  good  job  of  plowing  where  a 
solid  mouldboard  entirely  fails.  These  bottoms  are  also 
exceedingly  useful  for  plowing  black,  waxy  and  clay 
soils  in  which  an  ordinary  plow  bottom  fails  to  scour. 
The  share  is  made  with  a  comparatively  straight  edge 
to  give  a  straighter  cutting  surface  to  the  share. 


108 


THE  OLIVER  PLOW  BOOK 


Illustration  K 

Illustration  K  is  a  stubble  bottom  designed  for  use  in 
waxy  soils  and  the  lighter  prairie  soils  where  scouring 
troubles  prevail.  This  bottom  is  particularly  adapted 
to  work  in  those  soils  that  have  a  tendency  to  stick  to 
the  mouldboard,  but  are  rather  loose  in  their  composi- 
tion. For  this  reason  the  share  and  mouldboard  are 
shaped  to  cause  as  little  breaking  of  the  soil  as  possible 
until  it  leaves  the  mouldboard.  The  furrow  is  turned 


A  type  of  soil  in  which  the  above  illustrated  mouldboard  is  in  common 
use.  A  glance  at  this  picture  is  sufficient  to  show  that  the  plowmaker's 
problem  is  a  difficult  one. 


slightly  more  than  half  over.  On  account  of  these 
features  this  bottom  is  not  adapted  to  plowing  sod.  The 
unusually  sharp  point  and  narrow  angle  formed  by  the 
landside  and  share  give  this  bottom  great  penetration, 


PLOW  BOTTOMS 


109 


a  feature  which  is  absolutely  necessary  in  the  types  of 
soil  to  which  this  bottom  is  adapted.  The  shape  of  the 
share  and  mouldboard  is  such  that  the  earth  exerts  an 
even  pressure  upon  the  bottom  from  the  time  the  share 
strikes  it  until  it  is  turned  over  on  the  furrow  side. 


Illustration  L 


Illustration  L  depicts  a  bottom  popularly  known  as  a 
Scotch  type  and  is  for  use  in  turning  soils  in  those 
countries  where  clay  land  predominates  and  where  rain- 
fall is  excessive.  The  share  is  narrower  than  the  mould  - 


The  work  of  the  plow  bottom  shown  in  illustration  L  reveals  that  the 
earth  is  turned  over  with  little  or  no  pulverizing.  This  is  necessary  for 
underdraining  and  to  give  the  furrow  slice  on  top  an  opportunity  to  dry 
out  so  that  it  can  be  successfully  tilled. 


1 10  THE  OLIVER  PLOW  BOOK 

board,  consequently,  a  portion  of  the  furrow  is  not  cut 
entirely  off.  The  mouldboard  pushes  the  cut  part  of 
the  furrow  solidly  against  the  preceding  furrow,  shaping 
the  furrow  to  leave  the  top  diamond  shaped,  and  drain- 
age facilities  on  the  bottom. 


Illustration  M 

Illustration  M  shows  a  chilled  bottom  made  for 
handling  all  kinds  of  gritty,  sandy  soils,  and  also  clay 
lands  that  are  not  sticky.  This  bottom  is  made  with  a 
sloping  landside.  When  the  plow  picks  up  the  dirt  to 
turn  it  over,  the  lower  outside  edge  of  the  furrow  slice 
acts  as  a  fulcrum  over  which  the  furrow  turns.  When 
the  furrow  is  raised  into  a  position  almost  vertical  the 
dirt  falls  of  its  own  weight  because  there  is  nothing  to 
prevent  its  downward  motion.  As  the  earth  begins  to 
fall  it  naturally  crumbles,  filling  the  lower  portion  of  the 
furrow  with  loose  pulverized  soil.  The  advancing  mould- 
board  finishes  the  work  by  turning  the  rest  of  the 
furrow  on  top. 

This  process  of  plowing  is  exceptionally  good  for 
sandy  soils  because  it  insures  a  thorough  circulation  of 
air  in  all  parts  of  the  furrow  slice.  Another  advantage 
of  the  sloping  landside  is  that  the  shin  acts  upon  the 
earth  very  much  in  the  same  manner  as  a  knife 
acts  upon  a  piece  of  wood  when  operated  with 


v/r..:>^u»  v  J»T  •••"'  ••'•<>•*'    41-!  >»-<> 

/•• '  K-'-Mlf^  />^^  «    IM^ 

-'    *•.•'•!        1    '-f  ,\   ijF/C  -  /^/i.  •     \  ••/.'••  V*| 

w; 

^ f   •  ;>-  ^    </'  j( -  •'"'^jV *•  S' ;'.*^w;^''i' !' Sir' 


1 12  THE  OLIVER  PLOW^BOOK 

a  slanting  cut.  This  also  has  a  tendency  to  make 
the  plow  pull  lighter  in  draft  than  a  plow  with  a 
straight  landside. 

These  few  illustrations  serve  to  show  that  it  is  highly 
important  to  select  a  plow  bottom  for  handling  the  soil 
the  way  it  should  be,  and  also  that  when  any  doubt 
exists  to  consult  a  plow  expert  before  a  radical  change 
is  made  in  bottoms. 

Generally  speaking,  the  type  of  plow  bottom  that 
does  the  best  work  pulls  the  hardest  because  the  old 
law  that  so  much  energy  is  required  to  produce  a  given 
amount  of  work  is  applicable  to  plow  bottoms.  Less 
power  is  required  to  break  a  clod  into  three  parts  than 
into  a  million.  The  breaking  of  earth  into  finer  particles 
is  highly  important  if  the  proper  seed  bed  is  to  be 
prepared. 

Tests  have  been  made  which  show  that  mouldboards 
curved  to  do  the  pulverizing  require  more  energy  or 
power  than  the  bottoms  which  break  the  soil  into 
clods.  The  four  illustrations  showing  sectional  views  of 
plowing  are  the  results  of  a  test  made  purposely  to  deter- 
mine whether  the  plow  bottom  that  did  the  best  pul- 
verizing pulled  heavier  than  the  one  that  did  the  inferior 
grade  of  work.  This  test  was  made  in  a  field  of  very 
heavy  clay  and  sand  not  in  a  loamy  combination.  It 
had  not  rained  for  several  weeks.  All  the  tests  were 
made  in  the  morning  of  the  same  day  in  order  that  there 
should  be  as  little  change  as  possible  in  the  moisture 
content  of  the  ground.  The  only  difference  in  the  plow 
bottoms  was  in  the  shape  of  the  mouldboards.  Thus,  the 
condition  for  all  the  plows  was  the  same,  the  only  dif- 
ferent contributing  factor  being  the  mouldboard. 


PLOW  BOTTOMS 


113 


Figure  1 


Not e  the  thorough  pulverization  of  the  soil,  the  foot  prints  which  show 
the  dry  condition,  and  the  absence  of  air  spaces. 


Figure  1  shows  a  job  of  plowing  almost  ideal.  One 
would  not  expect  it  in  soil  as  dry  and  hard  as  this  but 
the  plow  pulled  14%  heavier  than  the  plow  bottom 
which  did  the  poorest  work,  or  that  shown  in  Figure  4. 


Figure  2 

This  plowing  is  not  so  well  pulverized  as  that  shown  in  Figure  I ,  but 
it  could  be  regarded  as  a  fairly  good  job  of  plowing  dry  soils. 


The  plowing  shown  in  Figure  2  is  not  so  good  as  that 
Figure   1.     The  ground  is  not  as  finely  pulverized. 
The  plow  bottom  pulled  4%  lighter. 


in 


114 


THE  OLIVER  PLOW  BOOK 


Figure  3 

The  clods  are  larger  than  those  shown  in  either  of  the  two  previous 
illustrations.  The  air  spaces  at  the  bottom  of  the  furrow  slice  are  more 
pronounced,  and  the  furrow  slice  shows  cloddy  formations  rather  than 
pulverization. 

The  work  in  Figure  3  shows  that  the  earth  was 
turned  up  into  clods.  There  is  little  pulverization. 
The  bottom  used  in  doing  this  work  pulled  13%  lighter 
than  the  one  that  did  the  work  shown  in  Figure  1 . 


Figure  4 

Clods  are  larger  than  in  Figure  3.  The  furrow  slices  are  unevenly 
formed.  They  are  merely  larger  clods  intermingling  with  smaller  ones 
and  the  finer  soil  particles.  There  is  no  indication  of  pulverization 
which  is  necessary  for  the  proper  aeration  of  the  soil. 

The  plowing  done  in  Figure  4  shows  the  ground  broken 
into  large  clods,  little  or  no  pulverization  and  very  im- 
perfect furrow  slices.  This  job  required  less  power  by 
1 4%  than  the  one  shown  in  Figure  1 . 


PLOW  BOTTOMS  1 1 5 


When  one  considers  that  the  pulverization  of  the  soil 
is  vitally  necessary  in  by  far  the  greatest  number  of 
cases  he  will  pay  less  attention  to  the  draft  of  the  bottom 
and  more  to  its  adaptability.  Sufficient  power  should  be 
used  to  do  the  work  well. 

An  experiment  was  made  with  the  bottoms  shown  in 
illustrations  F,  G,  K  and  M  to  determine  just  what  effect 
different  shaped  mouldboards  have  upon  the  soil.  This 
experiment  was  made  in  a  field  of  clay  soil  thoroughly 
saturated  with  water.  It  was  necessary  to  perform  such 
an  experiment  with  a  soil  that  would  hold  together 
sufficiently  to  make  observations.  Wet  clay  is  the  best 
kind  of  soil  for  this  purpose. 

These  four  types  of  plow  bottoms  are  for  use,  as  the 
descriptions  read,  in  widely  varying  soils.  The  illus- 
trations of  the  work  done  by  these  bottoms  in  the  soils 
for  which  they  are  adapted,  when  compared  with  these 
illustrations,  must  forcibly  call  attention  to  the  impor- 
tance of  selecting  a  plow  bottom  adapted  to  the  soil. 
These  experiments  were  conducted  in  the  morning  of  the 
same  day  in  order  that  the  moisture  content  should  be  as 
nearly  uniform  as  possible. 

These  illustrations  also  show  the  relative  work  done  by 
the  share,  mouldboard  and  landside  in  such  a  way  as  to 
call  attention  to  the  difficulty  encountered  in  trying  to 
establish  a  fixed  center  of  draft  that  will  serve  as  a  guide 
for  all  shaped  plow  bottoms  and  soils. 

While  this  question  would  be  more  properly  discussed 
in  the  chapters  on  plow  hitches,  these  illustrations  are  so 
pertinent  that  the  reader's  indulgence  for  this  deviation 
from  good  sequence  is  asked. 


116 


THE  OLIVER  PLOW  BOOK 


The  right-hand  side  of  the  furrow  slice  is  laid  on  the  furrow  bottom 
in  such  a  way  that  the  forward  travel  of  the  mouldboard  will  give  it  a 
pinching,  crushing  motion  to  separate  the  soil  particles. 


In  the  seventh  paragraph  of  this  chapter  the  plow 
bottom  is  referred  to  as  a  three-sided  wedge. 

The  mouldboard  and  upper  part  of  the  share  form  the 
curved  wedge  shape  part  which  separates  the  soil  parti- 
cles while  turning  them  over.  For  the  sake  of  clearness 
in  this  discussion  the  work  of  the  plow  bottom  is  divided 
into  three  parts:  first,  the  share,  cutting  the  furrow  sole; 
second,  the  shin,  cutting  the  furrow  wall;  third,  the 
mouldboard,  lifting,  stretching,  turning  and  compacting 
the  furrow  slice  into  an  inverted  position. 

The  relative  amount  of  work  that  the  shin,  the  mould- 
board  and  the  share  do  is  exceedingly  hard  to  figure.  It 
is  very  doubtful  whether  an  absolute  center  of  draft  can 


PLOW  BOTTOMS 


117 


A  section  of  the  furrow  shown  in  the  illustration  on  page  116  cut 
farther  forward,  showing  that  the  plow  bottom  has  forced  the  furrow 
slice  to  conform  to  its  shape,  thereby  beginning  a  stretching  operation  on 
the  bottom  of  the  furrow.  Observe  in  the  illustration  on  page  116  that 
after  the  furrow  slice  has  reached  the  ground  the  freshly  stretched 
furrow  slice  bottom  is  helping  to  put  pressure  against  the  top. 


A  plow  bottom  which  does  not  have  the  proper  shape  to  force  the 
furrow  slice  against  its  surface  so  that  the  pressure  is  equal  on  all  parts 
of  the  plow  bottom.  This  illustration  shows  the  importance  of  having 
a  plow  bottom  adapted  to  the  soil.  The  shin  is  doing  the  greater  part  of 
the  worfy. 


118 


THE  OLIVER  PLOW  BOOK 


The  work  of  this  bottom  shows  remarkable  adaptability  to  this  type 
of  soil.  The  squeezing,  pinching  motion  of  the  mouldboard  by  forcing 
the  furrow  slice  against  the  bottom  of  the  furrow  is  plainly  noticeable. 
This  mouldboard  is  doing  more  work  than  the  one  illustrated  on  page  120. 


be  determined  for  all  conditions.  Enough  experimenting 
has  been  done  to  show  that  the  center  of  draft  can  be 
approached  closely  enough  for  practical  purposes. 

When  once  the  center  of  draft  has  been  determined  it 
is  obvious  that  the  amount  of  work  being  done  on  all 
sides  of  this  point  must  be  equal  in  weight.  Measuring 
the  distance  from  this  point  to  all  the  extremities  of  the 
mouldboard  and  share  will  give  sufficient  measurements 
to  figure  the  percentages.  The  result  will  be  close 
enough  for  all  practical  purposes. 


PLOW  BOTTOMS 


119 


The  furrow  slice  shown  in  the  illustration  on  page  118  cut  farther 
forward.  The  plow  bottom  forces  the  furrow  slice  against  it  in  such  a 
way  that  the  complete  furrow  slice  taJ^es  on  the  curvature  of  the  mould- 
board.  This  means  a  rearrangement  of  the  soil  particles  from  the  top 
of  the  furrow  slice  to  the  bottom. 

Another  way  for  determining  the  relative  draft  of  the 
share  and  mouldboard  is  to  remove  the  mouldboard  from 
the  plow,  then  start  the  plow  in  a  furrow  the  proper 
width  and  depth  previously  prepared  with  the  end  of 
the  furrow  slice  cut  squarely,  and  the  furrow  wall  the 
depth  of  the  furrow  far  enough  ahead  for  the  experiment. 
A.  dynamometer  will  show  the  relative  lifting  work  done 
by  the  point  and  wing  of  the  share.  The  plow  must 
stop  as  soon  as  the  earth  has  been  lifted  the  height  of 
the  share. 

Putting  the  mouldboard  back  on  the  plow,  and  lifting 
the  furrow  slice  which  has  been  measured  the  proper 
width  and  cut  the  full  depth  until  it  is  ready  to  drop  into 
position,  will  obviously  determine  the  amount  of  work 
required  by  the  share  and  mouldboard.  Subtracting 
the  difference  between  this  amount  and  that  required  by 


120 


THE  OLIVER  PLOW  BOOK 


The  furrow  slice  is  being  picked  up  and  turned  over  very  much  as  a 
cal^e  of  ice,  without  any  perceptible  pulverization  of  the  ground.  Observe 
that  the  bottom  of  the  furrow  slice  does  not  rest  against  the  furrow  bottom 
except  the  loose  particles  that  have  broken  off  and  have  fallen  down. 
Observe  the  center  of  draft  on  this  plow  is  lower  than  the  one  shown  on 
page  118. 

the  share  will  give  the  amount  of  work  done  by  the 
mouldboard.  Using  the  entire  plow  without  cutting  the 
furrow  wall  gives  the  amount  of  work  required  by  the 
shin  to  cut  the  furrow  wall,  the  share,  the  sole,  and  the 
mouldboard  to  crush  and  invert  the  furrow.  Experi- 
ments of  this  kind  have  been  conducted  with  widely 
diversified  results. 

A  test  was  made  using  what  is  known  as  the  Scotch 
type  of  plow  bottom.  The  ground,  clay  sod,  was  being 
plowed  six  and  one-half  inches  deep  and  eleven  inches 
wide.  The  amount  of  work  done  by  the  share  was  forty 
per  cent,  of  the  total,  the  lifting  and  placing  by  the 
mouldboard,  forty  per  cent,  and  cutting  the  furrow  wall 
by  the  shin  twenty  per  cent. 


PLOW  BOTTOMS 


121 


The  furrow  slice  the  same  as  shown  on  page  120  cut  farther  forward. 
This  furrow  shows  no  indication  of  pulverization  but  a  tendency  to  lift 
the  slice  from  the  start. 


Another  experiment  with  an  entirely  different  shaped 
bottom  cutting  six  inches  deep  and  fourteen  inches  wide 
revealed  the  following  result.  Thirty-three  per  cent,  of 
the  work  was  done  by  the  share,  forty-seven  per  cent, 
by  the  mouldboard,  and  twenty  per  cent,  by  the  shin 
cutting  the  furrow  wall.  The  type  of  soil  in  which  the 
experiment  was  conducted  was  a  clay  loam  sod. 

In  both  instances  the  draft  of  the  plow  was  arranged 
so  that  there  was  no  pressure  of  the  landside  against  the 
furrow  wall. 

The  amount  of  work  required  of  the  landside  is  solely 
determined  by  the  hitch.  If  the  hitch  is  properly  made 
there  is  little  landside  pressure  because  the  land  suck  on 


122  THE  OLIVER  PLOW  BOOK 


A  type  of  mouldboard  which  breads  this  wet  clay  soil  into  large  clods. 
Notice  the  bluffness  and  the  effect  upon  this  soil.  It  ought  not  require 
any  argument  to  show  that  this  plow  is  not  adapted  to  this  type  of  soil. 
Breaking  soil  into  clods  is  not  plowing. 


the  share  and  shin  cuts  away  the  earth,  leaving  the  land- 
side  free  from  coming  in  contact  with  the  furrow  wall. 
However,  in  actual  practice  this  condition  does  not  pre- 
vail. 

It  has  been  found  that  the  pressure  of  the  landside 
against  the  furrow  bank  caused  by  incorrect  hitching 
increases  the  total  draft  of  a  plow  bottom  from  fifteen  to 
forty  per  cent.,  depending  upon  the  kind  of  soil  being 
plowed  and  the  distance  the  hitch  is  away  from  the 
center  line  of  draft. 

This  statement  with  reference  to  the  pressure  of  the 
landside  immediately  suggests  the  point,  why  have  a 
landside  on  a  plow  if  there  should  be  no  pressure  against 
the  furrow  bank  ?  There  must  be  some  means  for  keep- 
ing the  plow  from  swerving  to  one  side  whenever  the 
share  strikes  some  obstruction  that  causes  a  sudden 
shifting  in  the  center  of  draft  of  the  plow  bottom.  For 


PLOW  BOTTOMS 


123 


In  view  of  the  fact  that  breaking  the  soil  particles  is  necessary  for 
the  proper  making  of  the  seed  bed,  the  question  often  confronts  those  who 
have  stony  ground  as  to  how  they  can  plow  so  that  the  bottom  will  pene- 
trate the  ground  immediately  after  the  stone  has  been  passed.  The  illus- 
tration shows  how  one  farmer  is  accomplishing  this  work-  On  account 
of  the  rapidity  with  which  this  type  of  soil  dries  out  it  is  highly  im- 
portant that  there  be  the  fewest  possible  unplowed  stretches  of  ground. 

example — if  a  plow  should  strike  a  snag  on  the  wing  of 
the  share  the  center  of  draft  of  the  plow  is  suddenly 
changed  to  a  point  near  the  wing.  The  landside  press- 
ing against  the  furrow  wall  holds  the  plow  in  its  true 


124 


THE  OLIVER  PLOW  BOOK 


Turning  an  in-corner  has  been  practiced  by  farmers  who  have  soils 
that  should  not  be  trampled  any  more  than  is  necessary  in  the  process  of 
plowing.  It  is  highly  important  that  the  furrow  be  turned  so  that  the 
ground  is  plowed  properly  if  the  best  results  are  to  be  obtained  from  this 
practice. 


line  until  the  obstruction  is  passed  and   the  center   of 
weight  returns  to  its  normal  position. 


As  a  matter  of  fact,  this  condition  is  constantly  taking 
place  in  the  soil.  The  soil  texture  changes  with  every 
inch  of  travel  and  some  means  must  be  provided  to  take 
care  of  rapid  and  continuous  changes.  The  shape  and 
size  of  the  landside  have  a  great  deal  to  do  in  this  con- 
nection. Obviously  there  must  be  enough  square  inches 


PLOW  BOTTOMS 


125 


This  clay  field  is  being  plowed  seven  inches  deep  to  permit  moisture 
to  escape.  This  field  was  tiled  but  on  account  of  the  imperciousness  of 
the  clay  excessive  water  remains  and  it  is  necessary  to  plow  in  such  a 
way  that  there  is  under-drainage.  Contrast  this  type  of  plowing  with 
that  shown  in  the  illustration  below. 


i 


When  plowing  sandy  loam  the  great  object  is  to  stir  the  ground  for 
aeration  and  leave  it  in  such  a  manner  that  moisture  will  not  unduly 
escape,  thus  the  crowning  of  the  furrows,  noticeable  in  the  illustration 
above,  is  entirely  absent  and  the  ground  left  as  level  as  possible.  These 
two  illustrations  are  good  evidences  of  the  fact  that  plowmakers  are 
striving  to  build  bottoms  that  will  do  the  soil  the  greatest  possible  good. 


of  landside  surface  to  prevent  the  plow  gouging  into  the 
furrow  wall  and  also  to  help  keep  the  plow  running  level. 
On  breaking  plows  the  shallow  furrow  requires  an  ex- 


126 


THE  OLIVER  PLOW  BOOK 


This  method  of  laying  the  furrow  when  plowing  sod  insures  the  fewest 
possible  air  spaces  and  vents  for  the  continued  growth  of  the  inverted 
grass  blades. 

ceptionally  long  and  narrow  landside  to  give  the  required 
surface.  On  stubble  and  general  purpose  plows  this 
surface  can  be  acquired  by  giving  more  height  and  not 


PLOW  BOTTOMS  127 


One  does  not  often  see  three  different  styles  of  plow  bottoms  on  the 
same  plow.  These  bottoms  are  all  cutting  the  same  width  and  the  same 
depth  but  notice  the  difference  in  the  delivery  of  the  soil.  The  front  plow 
bottom  is  doing  the  quality  of  work  this  soil  requires.  The  other  two 
are  not — the  middle  bottom  doing  better  work  than  the  rear  one.  The 
front  bottom  is  the  same  as  that  shown  in  illustration  G;  the  second, 
illustration  F;  the  third,  illustration  K.  Observe  in  the  work  °f  the 
front  bottom  that  the  soil  is  completely  turned  over  and  well  pulverized 
and  that  the  middle  bottom  turns  the  furrow  over  more  completely  than 
the  rear  one. 


so  much  length.  In  bottoms  that  are  made  for  deep 
plowing  more  attention  is  given  to  the  height  of  the 
landside  than  to  the  length  because  of  the  greater 
amount  of  work  being  done  by  the  mouldboard. 

The  amount  of  moisture  in  the  ground,  its  looseness 
and  compactness,  and  amount  of  stubble,  trash,  roots 
and  sod  are  determining  factors  in  the  draft  of  plow 
bottoms.  Too  much  moisture  in  the  ground  adds  draft 
in  the  same  manner  as  not  enough  moisture.  Daily 
changes  in  moisture  cause  great  changes  in  draft. 


128  THE  OLIVER  PLOW  BOOK 


Shallow  plowing  of  sods  puts  more  work  on  the  share 
and  less  on  the  mouldboard.  Deep  plowing  of  sod 
lessens  the  work  of  the  share  and  puts  more  work  on  the 
mouldboard.  The  same  is  true  of  stubble. 

The  curvature  of  the  upper  part  of  the  share,  the 
mouldboard,  and  the  angle  of  the  mouldboard  to  the 
furrow  slice  have  to  do  with  the  pulverizing  qualities  of 
the  bottom  as  well  as  the  draft. 

The  increase  in  the  speed  of  a  plow  in  dry,  hard 
plowing  aids  materially  in  better  pulverization,  but 
while  it  is  doing  better  work  it  increases  the  power  re- 
quired. A  plow  bottom  shaped  to  do  the  proper  work 
at  a  speed  of  two  and  one-half  miles  an  hour  will 
throw  the  dirt  from  two  to  three  times  as  far  when 
travelling  at  twice  that  rate  of  speed. 


CHAPTER  XIII 


Plow  Bottom  Metals 

THE  farmer  is  often  in  doubt  as  to  whether  he  should 
use  a  chilled  or  steel  plow.     A  knowledge  of  chilled 
and  steel  metals  as  used  in  plows  will  enable  a  farmer 
to  determine  for  himself  which  type  of  plow  he  needs. 

In  steel  plows  of  the  best  grade,  the  principal  wearing 
parts,  the  mouldboards  and  shares,  are  made  from  what 
is  known  as  soft  center  steel.  This  steel  is  composed  of 
three  layers  fused  together.  The  two  outside  layers  are 
very  high  carbon  to  insure  hardness.  An  extra  hard 
finish  or  temper  is  necessary  to  make  the  plow  scour. 
The  center  layer  is  of  low  carbon  to  impart  toughness 
to  prevent  the  breaking  of  the  brittle  outside  layers. 

Steel  plows  thus  made  are  successful  for  use  in  soils 
for  which  they  are  adapted.  The  mouldboard  of  a  steel 
plow  of  the  type  described  is  only  a  quarter  of  an  inch 
thick  and  the  grinding  and  polishing  necessary  to  finish 
the  surface  added  to  the  natural  wear,  of  course,  wear 
away  much  of  this  thickness  so  that  sometimes  the  soft 
center  becomes  exposed  and  the  plow  will  no  longer 
scour.  For  this  there  is  no  remedy  and  a  new  part  is 
necessary. 

While  steel  plows  are,  as  a  rule,  lighter  in  weight  than 
the  chilled,  when  it  comes  to  the  matter  of  draft  the 
chilled  plow  is  by  far  the  lightest  in  any  or  all  soils  for 
which  it  is  adapted.  The  draft  of  a  plow  is  determined 
not  so  much  by  the  shape  of  its  mouldboard  and  style  of 


130  THE  OLIVER  PLOW  BOOK 

share,  as  by  the  scouring  qualities  of  the  metal  which 
enter  into  its  construction. 

As  a  matter  of  fact,  tests  in  draft  of  plows  have  been 
made  in  the  agricultural  departments  of  universities. 
These  £fsts  have  shown  that  chilled  plows  are  lighter  in 
dn 


fo  process  has  yet  been  invented  whereby  steel  can 
tempered  hard  enough  to  prevent  sand  and  stones 
from  deeply  scratching  the  surface.  Any  farmer  who  has 
land  that  is  sandy  in  places  knows,  if  he  uses  a  steel 
plow,  that  it  refuses  to  scour  after  leaving  the  sandy 
parts  and  enters  the  black  or  sticky  land.  This  is 
caused  by  the  sand  scratching  the  steel,  leaving  a  feather 
edge  that  ruins  the  dirt  polish  and  makes  an  obstruction 
to  stop  the  shedding  of  the  dirt. 

Anyone  who  has  never  had  this  feature  called  to  his 
attention  can  observe  the  phenomenon  by  examining 
his  plow  the  next  time  he  plows  a  piece  of  land  in  that 
condition.  This  peculiarity  of  steel  makes  a  steel  plow 
an  exceedingly  poor  implement  to  use  in  any  soil  that 
has  sand,  gravel  or  stones  in  it,  because  the  plow  wears 
out  too  soon.  It  is  like  using  a  razor  to  sharpen  lead 
pencils — too  costly. 

There  is  a  type  of  land  that  steel  plows  turn  to  good 
advantage  and  much  better  than  chilled  plows  can,  in 
fact,  where  chilled  plows  will  not  work  at  all.  Light 
soils,  loams  free  from  sand,  gravel,  or  stones,  and  black, 
waxy  dirt  can  be  handled  most  successfully  with  the 
steel  plows,  because  they  have  in  them  the  properties 
necessary  to  make  the  dirt  polish  on  the  mouldboard 
without  scratching  it.  Wherever  this  condition  prevails, 
steel  plows  are  the  most  successful,  but  when  grit  is 
present  the  wear  on  the  thin  layer  of  hard  steel  on  the 


PLOW  BOTTOM  METALS 


131 


The  toft  of  a  steel  share  is  perfectly  smooth  and  has  as  uniform  hard- 
ness as  it  is  possible  to  make. 


Plow  gunnels  with  and  without 
a  piece  of  steel  welded  on  the 
bottom  for  reinforcing  the  point. 
This  metal  is  of  the  proper  carbon 
content  to  help  keep  the  point  from 
wearing  upward  on  the  bottom. 
It  is  illustrative  of  the  efforts  put 
forth  by  plow  makers  to  make  steel 
shares  as  durable  as  possible. 
The  projection  on  the  edge  of  the 
gunnel  gives  a  wider  welding 
surface  thereby  making  the  share 
stronger. 


The  bottom  side  of  the  share  showing  the  position  of  the  extra  piece 
of  steel  on  the  finished  product.     This  gives  strength  and  additional  wear. 


132  THE  OLIVER  PLOW  BOOK 

surface  soon  exposes  the  center  which  is  so  soft  that  it 
will  not  scour  in  any  soil. 

Chilled  plows  are  constructed  by  an  entirely  different 
process.  When  the  mouldboard  is  properly  made  it  has 
a  flinty  hardness  that  never  has  been  duplicated  in  steel. 
This  hardness  enables  a  chilled  mouldboard  to  much 
better  withstand  the  scratching  of  sand,  gravel,  stones, 
etc.  As  a  matter  of  fact,  there  is  no  scratching  that  will 
affect  the  scouring  qualities  of  properly  chilled  metal. 

As  a  result  the  more  a  chilled  mouldboard  is  operated 
in  sandy  soil  the  smoother  it  becomes,  and  the  higher 
polish  it  takes.  Long  experience  has  shown  that  used 
plows  have  a  better  polish  than  can  possibly  be  put  on 
in  the  factory.  This  peculiarity  of  chilled  metal 
makes  chilled  plows  scour  better  in  all  kinds  of  sandy, 
gravelly,  stony,  heavy  clay  soils,  and  the  silt  loams  that 
contain  silica,  potash,  lime,  iron  and  aluminum  oxide. 

The  chill,  as  plowmakers  call  the  term  of  hardening, 
crystallizes  the  metal  so  that  the  grain  is  edgewise  of  the 
mouldboard  instead  of  lengthwise.  This  means  that 
the  dirt  in  shedding  passes  over  the  ends  of  the  crystals. 

The  ends  of  the  metal  crystals  furnish  the  surface  for 
scouring.  For  this  reason  chilled  mouldboards  are  very 
hard  to  wear  out.  They  often  wear  twenty  years. 
Instances  are  known  where  they  have  worn  fifty  years. 
Chilled  mouldboards  have  been  used  until  the  edge  has 
been  worn  to  the  thinness  of  a  piece  of  paper  and  sharp 
enough  for  a  keen  cut  knife. 

The  thickness  of  a  chilled  mouldboard  is  about  %  to 
}/2  of  an  inch.  One-quarter  of  an  inch  of  this  entire 
thickness  is  made  of  chilled  metal,  consequently,  a 
mouldboard  will  wear  and  scour  until  the  entire  thick- 
ness of  the  chilled  portion  is  worn  away.  When  this  is 


PLOW  BOTTOM  METALS 


133 


The  shin  and  point  of  this  bottom  show  the  effect  of  sand  upon  steel 
bottoms.  This  sort  of  ground  causes  a  steel  bottom  to  wear  out  very 
quickly- 


metal.  This  sample  of  chilled  metal  showing  the  crystals 
turned  on  edge  explains  why  sand  does  not  wear  away  chilled  metal 
as  it  does  steel.  The  dirt,  passing  across  the  ends  of  the  crystals,  has  a 
tendency  to  polish  chilled  metal  rather  than  to  wear  grooves  in  it. 


134  THE  OLIVER  PLOW  BOOK 

compared  with  the  thin  layer  of  ^"  of  steel  on  the  soft 
center  steel  mouldboard,  one  can  readily  see  that  a 
chilled  mouldboard  will  outlast  three  steel.  This  fact 
is  what  gave  rise  to  the  statement  that  one  chilled  plow 
will  outwear  three  steel  in  gritty  conditions. 

Properly  chilled  plows  are  not  affected  by  rust.  The 
iron  being  needle  crystal  in  form  merely  corrodes  on  the 
end  of  the  needle.  The  operator  can  scour  a  chilled 
plow  that  has  been  exposed  to  the  deteriorating  weather 
conditions  for  a  long  time  in  a  few  feet  of  travel  with  the 
bottom  in  the  ground.  This  feature  of  chilled  plows  is 
in  great  contrast  to  steel  plows  which  rust  so  easily  that 
the  rust  occasioned  by  a  few  days'  exposure  often  makes 
them  hard  to  scour. 

From  the  foregoing  discussion  on  chilled  and  steel 
plow  bottoms,  it  is  obvious  that  many  farmers  can  use 
both  types  of  plows  to  good  advantage,  and  where  it  is 
possible  to  interchange  the  steel  wearing  parts  with 
chilled,  the  advantage  is  double  because  of  the  saving  in 
expense. 

Oftentimes  it  is  necessary  to  plow  in  the  summertime 
when  the  ground  is  hard  and  dry.     The  chilled  share 
being  much  more  resistant  to  the  hard  earth  will  enable 
a  plowman  to  do  better  work  by  using  chilled  shares. 
I 

Experiments  have  been  tried  many  times  to  determine 
the  amount  of  wear  of  chilled  and  steel  shares.  We 
quote  one  experiment  that  was  tried  for  this  purpose  and 
the  result.  A  two-bottom  tractor  plow  was  equipped 
with  a  chilled  and  a  steel  share  of  the  same  size  and  type, 
one  bottom  being  equipped  with  a  steel  share  and  the 
other  with  a  chilled  share.  The  ground  in  which  the 
experiment  was  tried  was  a  sandy  soil,  very  hard,  with 


PLOW  BOTTOM  METALS 


133 


This  piece  of  chilled  metal  was  buried  eight  years.  The  rusty  surface 
was  scratched  away  with  the  back  °f  a  knife  blade,  revealing  a  perfectly 
smooth  and  unfitted  surface  beneath. 


The  peculiarity 
of  the  way  each 
metal  wears  is 
plainly  discerni- 
'ble. 


The  points  of 
these  shares  are 
illustrated  on 
page  136. 


136 


THE  OLIVER  PLOW  BOOK 


STEEL 


NEW 


USED 

8 
HOURS 


some  stones  in  it.  The  test  was  made  the  first  of 
September.  The  steel  share  was  only  used  eight  hours 
and  the  chilled  share  fifty-one  hours,  thus  showing  that 
the  chilled  share  in  this  type  of  ground  would  outlast 
six  steel  shares. 


CHAPTER  XIV 


Scouring  Troubles 

ANY  man  who  has  ever  operated  a  plow  knows  what 
failure   to   scour   means.     A    plow    bottom    must 
scour  if  the  best  work  is  to  be  done. 

The  reason  why  plows  fail  to  scour  is  very  seldom 
the  same  in  any  two  fields,  yet,  underlying  all  these 
causes  are  five  fundamental  facts.  The  first  and  most 
common  cause  is  the  lack  of  an  earth  polish;  the  second, 
improper  plow  adjustment;  third,  soil  conditions;  fourth, 
soft  spots  or  inequalities  in  the  mouldboard;  and  fifth, 
the  shape  of  the  bottom  with  relation  to  the  soil  texture. 

The  easiest  way  to  overcome  the  lack  of  an  earth  polish 
is  to  take  the  plow  into  hard  ground  and  operate  it  until 
this  polish  appears.  A  new  plow  coming  from  the  fac- 
tory is  always  covered  with  varnish  or  lacquer.  This 
should  be  removed  before  attempting  to  make  the  plow 
scour.  In  removing  the  varnish  it  is  better  to  use  some 
varnish  remover  preparation  or  strong  lye  solution. 
Never  use  a  sharp,  steel  instrument  because  it  is  very 
apt  to  scratch  the  mouldboard.  Whatever  preparation 
is  used  none  of  it  should  be  left  on  the  plow  bottom  any 
longer  than  necessary  to  clean  the  bottom  because  a 
solution  that  is  strong  enough  to  quickly  remove  the 
lacquer  will  have  a  tendency  to  pit  the  surface  if  left 
on  for  any  length  of  time.  The  safest  rule  is  not  to 
leave  the  bottom^from  the  start  to  the  finish  of  the 
cleaning. 


138  THE  OLIVER  PLOW  BOOK 

When  a  plow  mouldboard  becomes  pitted  it  must  be 
polished  to  the  depth  of  pitting  before  it  will  scour. 

If  plows  have  this  high  earth  polish  and  fail  to  scour 
the  trouble  can  nearly  always  be  traced  to  soft  spots  in 
the  mouldboard,  or  to  the  soil  itself.  Assuming  that  the 
mouldboard  does  not  contain  soft  spots  and  the  soil  does 
not  contain  enough  silicon  to  scratch  the  mouldboard, 
the  trouble  may  be  caused  by  the  plow  not  running  in  a 
true  line  of  draft,  or  the  soil  is  too  loose  for  the  proper 
amount  of  pressure  to  cause  the  mouldboard  to  shed 
properly,  or  it  may  be  a  combination  of  all  these  causes. 

Side  draft  causes  the  mouldboard  to  work  out  of  its 
normal  position,  thus  making  unequal  pressure  of  the 
earth  on  the  mouldboard. 

The  remedy  for  this  trouble  is  to  adjust  the  hitch  so 
that  the  plow  bottom  works  in  its  normal  manner. 
Whenever  a  plow  fails  to  scour  it  is  always  advisable 
first  to  be  sure  that  the  plow  is  running  correctly.  If 
this  does  not  remedy  the  trouble  lowering  the  plow  an 
inch  or  two  will  put  more  pressure  against  the  mould- 
board,  thus  forcing  off  the  earth  which  may  be  clinging 
to  the  bottom.  It  may  be  necessary  to  operate  at  this 
extra  depth  long  enough  to  put  on  a  new  polish.  Often 
times  lowering  the  bottoms  and  travelling  a  distance  of 
fifteen  to  twenty  feet  will  suffice. 

Occasionally  soils  which  scour  readily  have  spots  in 
them  that  cause  the  plow  to  stick.  These  spots  are 
nearly  always  the  result  of  a  change  in  the  soil  texture. 
That  is,  the  spots  where  the  plow  sticks  are  caused  by 
the  soil  being  looser.  If  the  driver  will  watch  these 
places  very  carefully  he  can  frequently  cause  the 
plow  to  scour  readily  by  increasing  the  speed  when  passing 


SCOURING  TROUBLES 


139 


A  type  of  soil  in  which  mouldboard  plows  were  never  known  to  scour. 
Observe  the  soil  sticking  to  the  handle  and  the  beam.  .  This  soil  is  of  that 
type  in  which  the  soil  particles  have  greater  affinity  for  other  substances. 
Plow  mouldboards  covered  with  plaster  of  Paris  and  hog  hides  have  been 
known  to  turn  this  soil  much  more  successfully  than  any  metal. 


Sectional  view  of  ground  plowed  in  the  above  manner.  The  ground 
is  merely  pushed  to  one  side  and  the  top  looks  as  though  it  might  have 
been  broken  up  with  any  kind  of  an  implement.  These  soils  offer  the 
greatest  opportunity  for  students  who  are  interested  in  soil  culture. 


through,   thus  saving  himself  the  necessity  of  cleaning 
the  bottom  with  a  paddle. 

If  none  of  these  remedies  effect  a  cure  look  very  care- 
fully   at    the    mouldboard,    particularly    at    the    places 


140  THE  OLIVER  PLOW  BOOK 

where  the  earth  sticks.  If  the  surface  of  the  mould- 
board  has  a  cloudy  appearing  spot  and  is  darker  than  the 
surrounding  parts  of  the  mouldboard,  it  shows  that  this 
part  of  the  mouldboard  is  softer  than  the  rest.  The 
only  remedy  in  a  case  of  this  kind  is  a  new  mouldboard. 

If  the  surface  has  the  appearance  of  being  scratched 
and  the  earth  sticks  there  is  no  known  remedy  for  this 
trouble  because  a  mouldboard  plow  has  not  yet  been 
made  that  will  successfully  scour  in  this  type  of  soil. 
The  reason  is  that  the  soil  is  a  mixture  of  very  sharp 
sand  and  silt.  The  silt,  being  of  a  plastic  nature,  fills 
in  the  grooves  made  by  the  sand,  thus  destroying  the 
high  polish  of  the  mouldboard  and  making  it  absolutely 
impossible  for  the  plow  to  shed  properly  if  the  soil  is 
moist  enough  to  make  the  silt  plastic. 


The  scratched  mouldboard  cannot  shed  dirt  properly  whether  it  is  of 
the  variety  that  sticks  to  the  metal  or  not.  The  two  illustrations  on 
page  141  show  this  bottom  in  sandy  soil. 

Another  remedy  that  sometimes  works  to  advantage 
is  the  moving  of  the  coulters  to  the  landside  of  the 
bottom.  The  object  of  this  adjustment  is  to  put  an 
additional  weight  of  the  furrow  slice  upon  the  shin  of 


SCOURING  TROUBLES 


141 


This  bottom  was  used  in  a  sandy  soil  growing  alfalfa.  The  purpose 
was  to  find  out  whether  a  steel  plow  would  shed  this  soil  as  successfully 
as  a  chilled  plow.  The  illustrations  on  pages  142  and  143  show  the 
chilled  plow  in  the  same  field.  The  plow  was  drawn  back  in  the 
furrow  and  no  effort  made  to  clean  the  earth  from  the  mouldboard. 


This  illustration  shows  the  above  plow  in  alfalfa  sod.  Observe  that  it 
scours  in  one  place  and  does  not  in  another.  This  is  characteristic  of 
the  steel  plow  in  gritty  soils.  It  puddles  the  sandy  soil  which  is  bad  for 
aeration  and  helps  to  make  it  dry  out  quickly,  paradoxical  as  it  may 


142 


THE  OLIVER  PLOW  BOOK 


the  plow,  thus  causing  greater  pressure.  Sometimes 
the  coulters  should  be  well  forward,  particularly  when 
the  soil  is  loose,  because  the  action  of  the  coulter  picks 
up  the  fine,  loose  soil.  The  advanced  position  permits 
the  earth  to  drop  on  the  furrow  slice  sufficiently  in 
advance  of  the  plow  bottom  to  prevent  it  from  falling 
on  the  shin. 

Oftentimes  turning  the  plow  bottom  on  its  wing  will 
start  it  to  scour.  This  puts  more  pressure  upon  the 
mouldboard  and  is  a  very  good  thing  to  do  when  the 
trouble  is  caused  by  going  from  wet  to  dry  soils  or  vice 
versa. 


The  chilled  bottom  photographed  after  the  experiment  illustrated  on 
page  143.  Observe  there  are  no  scratches  on  this  mouldboard.  The 
dark  points  on  the  wing  of  the  share  and  end  of  the  mouldboard  show  the 
high  polish  that  the  gritty  soils  put  upon  this  bottom. 


If  it  is  noticeable,  in  all  these  different  attempts  to 
make  the  plow  scour,  that  the  earth  is  being  turned  over 
into  clods  and  not  pulverized  properly,  even  though  the 
plow  does  scour  for  a  few  feet,  the  wrong  bottom  is 
being  used.  The  wise  thing  is  to  get  in  touch  with  some 


SCOURING  TROUBLES 


143 


The  bottom  palled  back  from  the  soil  in  the  same  manner  as  the  steel 
was.  There  is  no  earth  sticking  to  the  mouldboard  nor  is  there  any 
indication  of  puddling  of  the  soil. 


Observe  the  plow  is  scouring  all  the  time  and  that  the  soil  has  the  ap- 
pearance of  being  pulverized  and  well  turned  even  though  growth  of 
alfalfa  was  vigorous. 


reputable  plow  manufacturer  at  once  and  have  him 
send  an  expert  to  look  over  the  situation.  All  plow 
bottoms  are  designed  for  the  express  purpose  of  invert- 
ing the  earth.  It  is  not  possible  to  design  any  one  type 


144  THE  OLIVER  PLOW  BOOK 

of  mould  that  will  turn  all  the  different  soils  equally  well. 
The  fact  that  clay  soils  hold  together  means  that  a  plow 
to  successfully  turn  and  pulverize  them  must  not  have 
so  bluff  a  mouldboard  as  is  required  for  turning  loose, 
sandy  soils.  The  tendency  of  clay  particles  for  holding 
together  removes  the  necessity  for  as  much  bluff  ness  and 
curvature  in  the  mouldboard.  As  soils  vary  from  one 
extreme  to  the  other,  so  must  builders  make  plow  bottoms 
to  meet  these  variations. 

As  a  matter  of  fact,  plow  manufacturers  have  a  large 
variety  of  plow  bottom  combinations  in  order  to  prop- 
erly plow  soils  of  different  textures. 

It  is  a  peculiar  fact  that  in  the  waxy  soils  of  Texas, 
plow  mouldboards  have  been  made  of  steel,  iron,  glass, 
brass,  aluminum,  plaster  of  Paris,  and  hog  hides.  The 
peculiar  part  is  that  the  plaster  of  Paris  and  hog  hide 
mouldboards  worked  more  successfully  in  these  soils 
than  any  other  type  of  mouldboard  that  has  been 
invented. 

Whether  the  shape  of  a  mouldboard  has  everything  to 
do  with  its  scouring,  assuming  that  it  has  the  proper 
degree  of  hardness,  is  a  question  open  to  debate.  The 
experiences  gleaned  from  trying  to  develop  a  mould- 
board  that  would  work  successfully  in  the  waxy  soils 
of  Texas  developed  so  many  sizes,  styles  and  shapes  of 
plow  bottoms  that  the  plow  bottom  graveyard  is  full  to 
overflowing.  These  experiences  must  be  regarded  as 
very  strong  evidence  that  something  is  required  other 
than  the  shape  of  the  mouldboard  and  the  material  from 
which  it  is  made. 


SCOURING  TROUBLES 


145 


A  never  failing  way  to  determine  the  soft  spots  in  a  mouldboard  is  to 
take  an  old  file  and  break  it  so  that  a  sharp  edge  results.  Run  this 
lightly  over  the  mouldboard.  The  file  will  slide  smoothly  over  the  hard 
parts.  It  will  stick  t°  the  soft  spots.  Plow  manufacturers  are  always 
desirous  of  having  their  plows  give  satisfaction.  After  a  little  exper- 
ience of  this  kind  it  will  be  easy  to  detect  soft  spots  in  mould  boards  from 
their  cloudy  appearance.  Soft  spots  never  take  the  high  polish  that  the 
rest  of  the  board  does. 


The  reason  given  for  the  success  of  the  plaster  of  Paris 
board  is  that  the  plaster  wears  away  with  the  earth. 
This  demonstrates  that  the  adhesive  force  between  the 
earth  and  the  plaster  is  greater  than  the  cohesive  force 
of  the  plaster.  It  also  demonstrates  that  the  cohesive 
force  of  the  earth  is  greater  than  that  of  the  plaster  of 
Paris. 


146  THE  OLIVER  PLOW  BOOK 

The  plaster  wears  away  rapidly  and  the  farmer  is 
obliged  to  recoat  his  mouldboard  often — sometimes 
as  often  as  every  night.  Considering  that  Texas 
farmers  have  different  sizes  and  shapes  of  plow  bottoms, 
it  is  plainly  evident  that  the  shape  of  the  bottom  does 
not  control  its  scouring  qualities.  The  revolving  disk 
is  the  only  type  of  steel  plow  at  the  present  time  that  is 
regarded  as  handling  this  soil  successfully,  but  the  disk 
plow  does  not  scour  in  these  soils,  showing  that  the  ad- 
hesive force  of  the  steel  disk  and  the  earth  is  greater  than 
the  cohesive  force  of  the  earth  and  also  that  the  co- 
hesive force  between  the  two  is  greater  than  the  adhesive 
force  of  the  earth  particles. 

If  it  is  a  question  of  constant  pressure  of  the  soil 
against  the  mouldboard,  it  is  necessary,  then,  in  the  design 
of  a  mouldboard  to  shape  it  to  interfere  as  little  as 
possible  with  the  crumbling  of  sticky  soils  when  turning 
them  over. 

It  is  far  from  easy  to  design  a  plow  bottom  that  will 
always  do  these  things  satisfactorily.  The  Texas  illus- 
tration must  be  regarded  as  conclusive  evidence  that 
the  shape  of  the  mouldboard  is  not  the  only  factor  to  be 
taken  into  consideration.  The  material  from  which  the 
mouldboard  is  made  and  the  way  it  is  made  often  have 
more  to  do  with  the  success  of  the  bottom  than  its  shape. 
Very  frequently  a  mouldboard  that  from  all  standpoints 
of  theory  should  do  a  better  job  than  another  type  of 
bottom  does  the  poorer  quality  of  work  simply  because 
the  mouldboard  fails  to  scour. 

Another  side  in  scouring  that  is  little  known  and  has 
received  but  spasmodic  attention  is  the  effect  of  heat 
upon  metal  mouldboards. 


SCOURING  TROUBLES  147 

One  time  a  plow  bottom  designer  was  trying  out  a 
bottom  in  sticky  soil.  The  field  was  wet  on  one  side 
and  dry  on  the  other.  The  day  was  fearfully  hot.  In 
the  morning  it  was  observed  that  the  plow  was  scouring 
successfully  in  the  wettest  and  driest  portions  of  the 
field  but  where  the  two  came  together  the  plow  refused 
to  scour  on  going  into  the  wet  portion  and  also  refused 
to  scour  on  coming  out.  At  noon  the  plow  bottom  was 
cleaned  and  left  standing  where  the  sun  had  a  good 
opportunity  to  thoroughly  heat  it.  The  plow  bottom 
became  very  warm  and  the  first  two  rounds  in  the  after- 
noon the  plow  scoured.  After  that  the  designer  en- 
countered the  same  trouble  he  had  experienced  in  the 
morning. 

It  is  a  matter  of  plow  history  that  a  Texas  farmer 
devised  a  pan  arrangement  back  of  the  mouldboard, 
well  down  towards  the  share,  to  hold  burning  corncobs. 
The  difficulty  experienced  in  this  device  was  the  lack  of 
uniform  heat  on  all  parts  of  the  plow  bottom.  Those 
who  witnessed  the  demonstration  maintained  that  the 
mouldboard  scoured  where  the  temperature  was  hot 
enough,  but  failed  to  scour  on  other  sections  of  the 
bottom. 

There  may  be  more  in  this  theory  than  some  of  us 
think  at  the  present  time  because  it  is  a  well  known 
physical  fact  that  heat  is  the  best  agent  for  separating 
molecules  combined  by  adhesive  force. 

Oftentimes  failure  to  scour  cannot  be  attributed  to 
any  one  cause.  It  may  be  a  combination  of  two,  three, 
or  more  of  the  conditions  mentioned  in  the  second  para- 
graph. The  operator  must  act  in  cases  of  scouring 
troubles  very  much  like  a  physician  diagnosing  compli- 
cations in  a  case  of  illness,  and  then  apply  the  proper 
remedies  for  each  trouble. 


148  THE  OLIVER  PLOW  BOOK 

Enough  has  been  said  to  show  that  a  dull,  or  incor- 
rectly shaped  share  can  do  irreparable  damage,  and  the 
operator  never  discover  the  source  of  the  trouble  unless 
he  takes  time  to  investigate. 

Incorrect  hitching  and  a  dull  share  combined  cause  a 
plow  to  do  so  many  erratic  things  that  the  share  symptom 
is  often  overlooked  in  seeking  to  rectify  the  trouble  by 
hitch  adjustments  alone. 


CHAPTER  XV 


Setting  the  Share  on  the  Plow 

KNOWING  how  to  drive  the  team  properly  and 
make  the  hitch  correctly  are  two  points  that  deter- 
mine good  plowmanship.  The  other  one  is  to  know  that 
your  plow  bottom  is  in  the  right  condition.  The  share  is 
the  vital  part  in  this  work.  If  the  operator  is  positive  the 
share  has  the  correct  shape  for  land  suck  and  penetration, 
he  has  little  to  worry  about  in  making  the  plow  work 
successfully.  A  plow  bottom  operating  correctly  cuts 
all  the  furrows  the  same  width,  the  same  depth,  and 
runs  level.  If  the  plow  is  not  doing  this  naturally,  some- 
thing is  wrong.  The  first  thing  to  investigate  is  the 
share. 

If  the  bottom  has  a  tendency  to  rise  when  the  hitch 
is  made  where  it  always  has  been  in  the  past  for  plow- 
ing that  depth,  the  plow  share  is  worn  rounding  on  the 
under  side,  giving  the  share  a  sled  runner  effect.  The 
tendency  is  to  work  out  of  the  ground  instead  of  into  it. 
Sharpening  the  point  is  necessary  to  rectify  this  trouble. 

If  the  furrow  bottom  is  uneven  and  full  of  gouged 
places,  the  plow  bottom  is  running  on  its  point.  If  the 
hitch  is  the  same  as  it  has  been  in  the  past  for  plowing 
at  this  depth,  the  trouble  is  that  the  point  of  the  share 
is  bent  downward  too  much,  causing  it  to  move  forward 
with  a  jumping  motion.  This  can  only  be  rectified  by 
putting  a  gradual  slope  on  the  point. 


150 


THE  OLIVER  PLOW  BOOK 


In  shafting  the  point  of  a  plow  share  the  greatest  care  should  be  ex- 
ercised to  see  that  it  has  a  gradual  wedged  shaped  slant.  One  of  the 
difficulties  encountered  when  carelessly  sharpening  shares  is  to  put  the 
point  of  the  share  oser  the  edge  of  the  anvil,  then  hit  it  a  blow  with  a 
hammer.  The  result  is  worse  than  the  equivalent  of  a  dull  share. 
Instead  of  the  ploio  going  in  deeper  as  intended,  it  gouges  along  the 
ground  and  increases  the  draft  of  the  plow.  The  illustration  shows 
the  proper  angle  and  shaping  of  the  point. 


The  wing  of  the  share  when  properly  sharpened,  rests  on  a  straight 
edge  with  the  point.  The  edge  of  the  throat  is  slightly  raised  from  the 
straight  edge.  This  means  that  when  the  plow  is  operating  in  the  ground 
the  point  is  as  much  low  as  the  throat  is  high  on  the  straight  edge. 


SETTING  THE  SHARE  ON  THE  PLOW 


151 


152  THE  OLIVER  PLOW  BOOK 

If  the  plow  bottom  has  a  tendency  to  pull  down  on 
the  point  so  as  to  bear  heavily  on  the  land  wheel  and 
lightly  on  the  furrow  wheels,  the  share  is  bent  upward 
too  much  on  the  wing.  To  remedy  this  the  wing  of  the 
share  must  be  lowered. 

If  the  plow  has  a  tendency  to  bear  down  heavily  on  the 
furrow  wheels  and  not  on  the  land  wheel,  there  is  too 
much  dip  or  suck  in  the  wing  of  the  share.  This  must 
be  rectified  by  raising  the  cutting  edge  of  the  wing. 

The  length  of  time  that  the  bearings  and  axles  of 
wheel  plows  wear,  providing  they  are  kept  properly 
greased,  is  largely  determined  by  the  correct  adjust- 
ment of  the  plow  bottom.  For  this  reason,  as  well  as 
that  of  good  plowing,  plow  shares  should  be  kept  sharp 
and  adjusted  correctly. 

These  are  delicate  operations  and  a  competent  smith 
or  plowman  should  be  consulted  if  the  operator  is  not 
absolutely  certain  which  course  to  pursue. 

The  share  of  a  walking  plow  has  more  wing  than  the 
riding  plow.  This  additional  wing  surface  is  necessary 
as  a  bearing  to  keep  the  plow  running  level.  On  sulky 
plows  the  wheels  carry  this  weight.  Hence,  when  the 
shares  of  wheel  plows  are  properly  sharpened,  only  the 
cutting  edge  comes  in  contact  with  the  ground.  The 
effect  of  the  wrong  set  on  a  share  is  immediately  notice- 
able in  a  walking  plow  and  is  identical  with  that  of  the 
wheel  plows.  The  operator  has  to  stand  the  brunt  of 
the  incorrect  adjustment  that  the  wheels  and  frame  of 
wheel  plows  sustain. 

When  one  remembers  that  the  point  of  the  share 
extends  a  slight  distance  landward  from  a  line  parallel 
with  the  landside  to  make  it  hold  the  land,  and  slightly 
downward  below  a  line  parallel  with  the  bottom  of  the 


SETTING  THE  SHARE  ON  THE  PLOW  153 

andslide  to  hold  it  in  the  ground,  and  the  wing  of  the 
share  with  edge  shaped  to  keep  the  bottom  working 
level,  he  will  have  little  difficulty  in  setting  a  share  on 
the  plow  bottom. 

Shares  and  bottoms  made  by  different  manufacturers 
have  differences  in  shapes,  but  the  general  principle  is 
the  same. 


CHAPTER  XVI 


Sharpening  Soft  Center 
Steel  Shares 

r*HE  majority  of  steel  shares  are  made  of  soft  center 
•1  steel,  a  term  applied  to  the  use  of  a  layer  of  low  carbon 
steel  between  two  of  high  carbon.  The  soft  center  steel  is 
by  far  the  most  common  steel  share  in  use  and  requires  a 
particular  treatment  in  sharpening  because  of  the  peculi- 
arity of  wear  upon  it.  Most  of  the  wear  on  the  share  takes 
place  on  the  underside,  hence  the  lower  layer  of  high 
carbon  steel  wears  away  faster  than  the  upper  one.  This 
must  be  observed  very  carefully  in  sharpening  the  share. 

In  heating,  care  should  be  taken  that  only  the  portion 
of  the  share  which  is  to  be  pounded  out  is  heated.  This 
can  be  done  by  laying  the  share  flat  with  the  edge 
over  the  center  of  the  fire  and  filling  up  the  underside 
with  green  coals.  This  keeps  the  greater  part  of  the 
share  cool,  thus  preserving  its  shape.  The  common 
mistake  is  to  put  the  share  in  the  fire  in  a  vertical  posi- 
tion with  the  edge  down.  This  heats  too  much  of  the 
share  and  causes  it  to  warp  and  spring  out  of  shape. 

The  pounding  should  be  done  from  the  upper  side  with 
the  bottom  of  the  share  flat  on  the  anvil.  This  keeps 
the  cutting  edge  down  and  works  the  hard  steel  of  the 
upper  surface  over  the  soft  steel  in  the  center,  thus  pre- 
serving for  the  share  a  hard  cutting  edge.  Since  shares 
receive  the  most  wear  on  the  under  side,  pounding  the 
share  on  this  side  exposes  the  soft  center  steel  and 
has  a  tendency  to  work  the  cutting  edge  out  of  shape. 


1 


f 


<X  w 

II 


156 


THE  OLIVER  PLOW  BOOK 


A  picture  of  a  soft  center  steel  share  pounded  on  the  upper  side.  The 
edge  has  the  appearance  of  being  somewhat  rough  but  the  hard  steel  was 
worked  down  over  the  edge.  Sometimes  in  heating  soft  center  steel 
shares  the  layers  of  steel  are  loosened.  Wherever  this  happens  pounding 
the  share  on  the  upper  side  keeps  it  from  wearing  away. 


Soft  center  steel  share  pounded  on  the  under  side  when  being  sharpened. 
Notice  that  the  hard  steel  on  the  surface  has  been  broken  away  on  the 
edge  and  on  the  point.  This  is  caused  by  improper  heating  when 
sharpening  and  pounding  the  share  on  the  under  side.  A  little  practice 
in  sharpening  soft  center  steel  shares  in  the  correct  way  and  an  under- 
standing of  how  to  set  them  on  the  plow  will  eliminate  a  great  deal  of  the 
difficulty  farmers  experience  in  the  operation  of  the  plow. 


After  the  point  has  been  hammered  on  the  anvil 
to  the  proper  shape,  if  necessary,  a  piece  of  steel  can 
be  welded  to  the  top  of  the  point. 

Care  should  be  taken  in  doing  this  work  not  to  dent 
the  share  when  hammering  it  out  as  this  would  spoil 
its  scouring  qualities. 


SHARPENING  SOFT  CENTER  STEEL  SHARES       157 

To  temper  the  share  properly  after  it  has  been  ham- 
mered out  requires  uniform  heat.  The  right  heat  is  a 
dull  cherry  red,  a  temperature  of  approximately  1 472°  F. 
One  of  the  most  successful  methods  of  tempering  is  to 
slowly  draw  the  share  through  the  fire  with  the  cutting 
edge  down  until  the  edge  has  been  heated  to  the  proper 
color.  Then  draw  the  share  from  the  fire,  put  the  point 
far  enough  into  the  ground  to  hold  up  the  share,  and  let 
it  stay  there  until  it  cools. 


CHAPTER  XVII 


Sharpening  Crucible  Steel  Shares 

/CRUCIBLE  steel  shares  are  made  of  one  piece  of  steel. 
^^  They  cannot  be  tempered  so  hard  as  soft  center 
steel  because  tempering  makes  them  too  brittle  and 
thus  subject  to  easy  breakage. 

Ground  that  sheds  easily  can  be  successfully  plowed 
with  a  crucible  share. 

Crucible  steel  shares  can  be  sharpened  exactly  the 
same  as  soft  center  steel  shares,  or  they  can  be  treated 
according  to  the  old  custom  of  pounding  the  share  on 
the  reverse  side.  However,  there  is  less  danger  of 
misshaping  the  edge  of  the  share  if  it  is  pounded  on 
the  upper  side. 


158 


CHAPTER  XVIII 


Sharpening  Chilled  Shares 

/^HILLED  shares  are  made  in  moulds  the  same  as 
^^  chilled  mouldboards.  On  account  of  the  nature  of 
the  iron  they  cannot  be  heated  and  drawn  out  by  pound- 
ing as  can  steel  shares.  When  it  becomes  necessary  to 
sharpen  chilled  shares  they  must  be  ground  on  the 
upper  side  on  an  emery  wheel  or  grindstone  until  a 
bevel  edge  appears. 


159 


CHAPTER  XIX 


The  Rolling  Coulter 

'  I  'HE  purpose  of  the  rolling  coulter  is  to  cut  the  stubble 
•••  and  trash  into  lengths  the  width  of  the  furrow  and 
leave  a  smooth  furrow  bank.  On  account  of  the  great 
difference  in  soil  texture  and  the  varieties  of  trash  dif- 
ferent adjustments  are  necessary  to  bring  about  this 
result. 

To  make  the  furrow  bank  smooth  the  rolling  coulter 
must  be  set  to  the  land  far  enough  away  from  the  plow 
shin  and  deep  enough  in  the  ground  to  prevent  the  shin 
of  the  plow  from  digging  into  the  furrow  bank  made  by 
the  rolling  coulter.  In  ordinary  conditions  the  coulter 
set  to  cut  a  furrow  J4"  to  Y%  wider  than  the  plow  bot- 
tom will  suffice,  but  by  no  means  can  anyone  assume  that 
this  is  a  set  rule  to  follow.  Set  the  coulter  so  that  it 
accomplishes  the  result  intended. 

One  must  remember  when  setting  a  coulter  to  properly 
cut  the  furrow  bank  that,  if  the  coulter,  when  set,  is  not 
running  parallel  with  the  landside  of  the  plow,  the  plow 
is  out  of  adjustment  and  the  bottom  must  be  correctly 
adjusted  before  the  rolling  coulter  can  be  finally  set. 
The  depth  at  which  the  rolling  coulter  operates  must  be 
determined  solely  by  conditions. 

In  cutting  trash  the  coulter  should  make  with  the 
surface  of  the  ground  a  condition  similar  to  a  shear  cut, 
using  the  ground  for  one  edge  of  the  shear.  In  order  to 
produce  this  shear  cut  with  the  rolling  coulter  it  is 
necessary  to  have  the  coulter  high  enough  to  force 


THE  ROLLING  COULTER 


161 


This  illustration  shows  the  effect  of  a  plow  out  of  adjustment  on  the 
rolling  coulter.  The  rolling  coulter  is  always  pulled  in  a  straight  line 
of  draft.  The  bottom  as  is  illustrated  by  the  landside  shows  that  it  is 
wording  out  of  its  true  line  of  draft.  The  clods  and  earth  on  the  edge  of 
the  furrow  bank  are  telltale  evidences  of  the  wrong  plow  adjustment. 


162  THE  OLIVER  PLOW  BOOK 

the  trash  down  and  under.  The  coulter  cannot 
do  this  if  it  is  set  deep  enough  in  the  ground  for 
the  downward  motion  at  the  cutting  edge  to  be  prac- 
tically straight.  For  this  reason  the  safest  rule  is  to  set 
the  coulter  deep  enough  to  cut  the  trash  without  clogging 
and  shallow  enough  to  cut  the  trash  without  riding  over 
part  of  it. 

When  operating  the  plow  in  hard  ground  the  coulter 
set  high  and  as  far  back  as  possible  gives  the  plow  point 
a  chance  to  penetrate  the  ground  first.  The  plow 
bottom  sucks  its  way  into  the  ground.  The  rolling 
coulter  must  be  forced  into  the  ground.  If  the  coulter 
is  placed  ahead  of  the  plow  point  part  of  the  suction  of 
the  bottom  will  be  utilized  in  pulling  the  coulter  into  the 
ground.  If  the  plow  point  penetrates  first  it  has  the 
advantage  of  the  weight  caused  by  deeper  penetration 
to  hold  the  coulter  in  the  ground. 

In  plowing  stony  ground  the  coulter  set  well  ahead  of 
the  point  and  very  low  prevents  stones  from  lodging 
between  the  coulter  blade  and  the  plow  bottom. 

A  little  study  of  these  fundamentals  will  soon  point 
the  way  for  properly  adjusting  the  coulter. 

The  Jointer 

The  purpose  of  the  jointer  is  to  turn  a  small  furrow  on 
top  the  furrow  slice  so  that  when  this  slice  is  inverted 
the  trash,  stubble,  sod,  etc.,  may  be  turned  to  the 
bottom  of  the  furrow. 

The  adjustment  of  the  jointer  is  very  much  simpler 
than  that  of  the  coulter.  It  should  be  set  so  that  the 
furrow  it  turns  should  rest  upon  the  larger  furrow  slice 


THE  ROLLING  COULTER 


163 


When  the  coulter  is  properly  set  the  furrow  wall  is  smooth  with  little 
or  no  dirt  on  the  unplowed  ground  next  to  the  furrow  wall.  The  clean 
cut  furrow  slices  and  the  absence  of  protruding  stubble  are  the  benefits 
of  a  correctly  set  combined  rolling  coulter  and  jointer. 


164 


THE  OLIVER  PLOW  BOOK 


Observe  the  jointer  turning  a  little  furrow  into  the  right-hand  corner 
of  the  big  furrow  bottom.     This  is  necessary  for  ideal  plowing. 


THE  ROLLING  COULTER 


165 


in  such  a  way  that  it  will  roll  into  the  lower  right  hand 
corner  of  the  furrow  when  the  slice  is  being  inverted. 
For  the  most  part  this  point  is  slightly  ahead  of  the 
point  of  the  plow  and  on  the  unplowed  land  J4"  to  M" 
from  the  shin  of  the  plow.  These  measurements  are  by 
means  fixed.  The  adjustment  must  be  made  to 


no 


bring  about  the  desired  results. 

The  jointer  cannot  be  used  by  itself  in  very  trashy 
ground  because  the  trash  will  catch  on  the  point  of  the 
shin  and  clog  the  throat  of  the  plow.  This  fact  led  to 
the  use  of  the  combined  rolling  coulter  and  jointer,  the 
adjustment  of  which  is  practically  the  same  as  that  of 
the  rolling  coulter  and  jointer  separately. 

The  Combined  Rolling  Coulter 
and  Jointer 

The  combined  rolling  coulter  and  jointer  is  a  recent 
improvement  in  plows  and  has  made  possible  the  suc- 
cessful covering  of  weeds  and  trash  in  the  lower  right 


The  combined  rolling  coulter  and  jointer  is  one  of  the  greatest  helps  for 
plowing  properly. 


166  THE  OLIVER  PLOW  BOOK 

hand  corner  of  the  furrow  where  they  interfere  very  little 
with  the  upward  trend  of  moisture  and  thus  rapidly 
help  make  humus  out  of  the  weeds. 

The  combined  rolling  coulter  and  jointer  is  the  only 
attachment  that  has  been  invented  for  use  with  plows 
which  absolutely  assures  that  all  kinds  and  sizes  of  trash 
will  be  buried  deep  enough  in  the  ground  for  the  suc- 
cessful eradication  of  insects  which  plowing  puts  out 
of  business.  Whatever  time  of  the  year  it  may  be  neces- 
sary for  plowing  it  is  always  advisable  to  have  that  plow 
equipped  with  a  combined  rolling  coulter  and  jointer 
and  to  see  that  all  trash  is  buried  on  the  bottom  of  the 
furrow. 


CHAPTER  XX 


The  Tractor  Plow  Hitch 

BEFORE  one  attempts  to  adjust  a  plow  he  should  know 
the  physical  laws  that  govern  the  operation  of  plows. 
Otherwise  he  is  groping  in  the  dark.  It  has  been  the 
experience  of  a  great  many  plow  experts  that  the  prin- 
ciples or  physical  laws  underlying  the  working  of  plows 
are  not  generally  understood.  For  this  reason  this 
chapter  will  treat  plow  adjustments  from  the  theoretical 
side  (which  after  all  controls  the  practical),  rather  than 
enter  into  a  discussion  of  how  the  operator  should  change 
the  hitch  to  produce  certain  results.  Another  reason  for 
treating  the  matter  from  the  physical  law  side  is  that 
specific  instructions  sometimes  produce  the  opposite 
from  the  intended  results.  This  happens  quite  often 
when  instruction  books  are  followed.  No  writer  of 
instructions  can  call  before  his  mind  all  the  different 
conditions  that  must  be  met;  consequently  the  best 
intentions  cause  trouble  by  the  reader's  inability  to 
diagnose  conditions  correctly. 

The  draft  laws  that  control  the  operation  of  tractor 
plows  are  the  same  for  wheel  and  walking  plows.  How- 
ever, different  adjustments  are  necessary  to  make  these 
different  types  of  plows  conform  to  the  basic  law  govern- 
ing proper  adjustments.  This  law  stated  very  specifi- 
cally is:  The  shortest  distance  between  two  points  is  a 
straight  line.  In  tractor  plow  adjustments  one  of  these 
points  is  the  "center  of  power"  of  the  tractor,  usually 
regarded  as  a  point  on  the  rear  axle  at  equal  distance 


168 


THE  OLIVER  PLOW  BOOK 


from  the  drivers.  The  other  point  is  the  "center  of 
draft"  (also  called  the  center  of  weight  or  the  center  of 
resistance)  of  the  plow.  A  straight  line  between  these 
points  is  the  "line  of  draft."  The  line  between  these 
two  points  is  theoretically  always  straight. 


Being  obliged  to  turn  the  front  tractor  wheels  toward  the  plowed  ground 
indicates  that  the  draft  of  the  plow  is  pulling  the  front  of  the  tractor  in 
the  opposite  direction.  This  is  hard  on  both  the  plow  and  the  tractor. 


The  center  of  draft  of  the  plow  is  an  imaginary  point 
in  the  plow  base  or  bottom  from  which  a  single  force 
pulling  straight  ahead  and  parallel  to  the  furrow  wall 
will  cause  the  plow  to  work  correctly  with  the  minimum 
effort.  This  point  is  usually  placed  from  12  to  15 
inches  back  from  the  share  point,  2  inches  up  from  the 
furrow  sole  and  3  inches  from  the  furrow  wall.  One 
must  remember  that  this  point  is  not  fixed  but  con- 


THE  TRACTOR  PLOW  HITCH 


169 


stantly  moves  from  side  to  side  and  up  and  down  on 
account  of  the  variations  in  shapes  and  the  intensity 
of  the  pressure  of  the  earth  against  the  bottom.  But 
for  the  sake  of  explaining  the  principle  we  will  assume 
that  this  point  is  correct.  In  actual  practice  a  slight 
variation  does  not  materially  affect  the  working  of  the 
plow. 


Being  obliged  to  turn  the  tractor  in  this  direction  shows  that  the  draft 
of  the  plow  has  a  tendency  to  pull  the  wheels  toward  the  plowed  ground. 
This  puts  enormous  end-thrust  on  the  front  of  the  tractor,  and  demands 
additional  power  for  operation. 

It  is  impossible  to  pull  a  plow  in  the  true  line  of  draft 
because  the  hitch  would  be  below  the  surface  of  the 
ground. 

The  fact  that  the  power  cannot  be  operated  in  a  line 
parallel  with  the  landside  through  the  center  of  draft  of 
the  plow  necessitates  two  lines  of  draft.  These  two 


170  THE  OLIVER  PLOW  BOOK 

lines — one  a  vertical  line  of  draft  (or  force)  tending  to 
pull  the  plow  out  of  the  ground  and  the  other,  the  line  of 
side  draft,  which  has  to  do  with  keeping  the  plow  oper- 
ating straight  ahead — determine  plow  adjustments. 
The  line  through  which  these  forces  neutralize  (or  the 
resultant  force)  is  the  true  line  of  draft  from  a  practical 
standpoint.  All  plow  adjustments  must  be  made  to 
keep  this  line  straight,  because  this  line  will  straighten 
theoretically  regardless  of  how  the  plow  or  the  tractor 
operates. 

When  we  understand  these  laws  and  what  is  necessary 
to  keep  the  line  between  these  two  points  straight,  that 
is,  between  the  center  of  power  and  the  center  of  draft, 
we  can  readily  see  why  it  is  necessary  to  have  the  plow 
beams  and  a  vertical  adjustment  to  take  care  of  the 
penetration  of  the  plow,  as  well  as  a  horizontal  adjust- 
ment to  take  care  of  the  side  draft. 

In  Fig.  5  is  illustrated  the  vertical  line  of  draft.  C  is 
the  center  of  draft  of  weight.  CX  is  the  theoretical  line 
of  draft.  B  represents  the  center  of  power  of  the 
tractor.  BGC  then  represent  the  line  of  draft  passing 
through  the  clevis  on  the  front  of  the  beam  of  the  plow 
at  G.  If  the  line  BGC  were  angled  as  BHC  and  the 
resistance  at  point  C  required  more  power  than  the 
force  necessary  to  straighten  the  line,  it  is  evident  that 
the  line  BHC  would  assume  the  position  BGC  before 
the  plow  would  move.  Hence  the  bottom  would  rise 
until  BHC  reached  the  position  BGC. 

Obviously  this  would  lessen  the  depth  of  the  plow 
regardless  of  the  fact  that  there  may  be  a  wheel  at  the 
rear  and  one  at  the  front.  If  the  front  wheel  happened 
to  be  the  controlling  factor  of  a  power  lift,  the  lift  would 
refuse  to  work  because  of  the  lack  of  weight  to  hold  the 


THE  TRACTOR  PLOW  HITCH 


171 


1 72  THE  OLIVER  PLOW  BOOK 

wheel  on  the  ground.  However,  it  is  easy  to  imagine  a 
hard  plowing  condition  where  the  plow  depth  would 
remain  the  same  and  the  effect  show  on  the  tractor. 
But  remember  that  whatever  happens  to  the  plow  or 
tractor,  the  draft  line  straightens. 

Suppose  the  plow  at  point,  C,  requires  550  pounds 
effort  to  move  ahead,  and  the  tractor  can  only  produce 
525  pounds  effort.  In  this  case  the  plow  would  remain 
stationary  and  point,  B,  the  center  of  power  of  the 
tractor,  would  lower  until  it  reached  the  line  AHC, 
providing  no  outside  influence  stopped  it.  If  point,  B, 
were  back  of  the  center  of  power  the  front  wheels  of  the 
tractor  would  rise.  If  point,  B,  were  ahead  of  the 
center  of  power  undue  weight  would  be  brought  to  bear 
on  the  front  trucks,  and  the  rear  wheels  of  the  tractor 
would  tend  to  slip  because  of  the  tendency  to  relieve 
them  of  weight.  When  this  condition  occurs,  as  it  often 
does,  the  operator  must  adjust  the  hitch  on  both  the 
plow  and  tractor  until  the  draft  line  is  straight. 

It  is  further  apparent  that  the  height  of  the  hitch  on 
the  tractor  and  the  range  of  clevis  adjustment  on  the 
front  of  the  plow  have  everything  to  do  with  keeping 
this  line  straight  when  plowing  at  different  depths. 

Theoretically  speaking,  a  different  adjustment  should 
be  made  on  a  vertical  clevis  every  time  the  plow  depth 
is  to  be  changed,  but  from  the  way  plows  are  designed,  a 
slight  variation  in  depth  can  be  made  without  materially 
affecting  the  draft  line.  However,  one  should  be  very 
careful  when  adjusting  the  plow  depth  to  vary  it  as 
little  as  possible  if  he  expects  his  plow  to  operate  per- 
fectly. 

Another  feature  of  the  vertical  adjustment  is  shown  in 
Fig.  5.  The  lines,  AHC  and  BGC,  show  that  the  different 


THE  TRACTOR  PLOW  HITCH  173 

distances  between  the  plow  and  the  tractor  necessitate 
different  adjustments  to  plow  the  same  depth.  In 
other  words,  the  farther  the  tractor  is  removed  from  the 
plow,  the  lower  it  is  necessary  to  hitch  in  the  vertical 
clevis  if  the  operator  desires  to  plow  at  the  same  depth 
as  when  the  tractor  is  hitched  to  the  plow  at  point  B. 

When  the  hitch  on  the  tractor  is  exceedingly  high  it 
may  become  necessary  to  lengthen  the  hitch  between  the 
plow  and  the  tractor  to  make  the  plow  run  at  the  depth 
the  operator  desires.  This  is  another  way  of  saying, 
keep  the  draft  line  straight. 

The  reader  will  permit  a  diversion  at  this  point  long 
enough  to  say  that  there  is  no  truth  in  the  theory  that  a 
short  hitch  makes  possible  lighter  draft  than  a  long 
hitch.  The  reason  for  this  is  very  plain  when  we  once 
understand  that  the  minimum  amount  of  draft  required 
to  pull  a  plow  must  be  through  a  straight  line  from  the 
center  of  draft  or  center  of  weight  to  the  center  of  power. 
As  long  as  the  tractor  and  plow  are  in  this  relation  the 
only  difference  is  the  weight  of  the  additional  length  ot 
the  draft  bar. 

It  is  further  apparent  from  Fig.  5,  that  if  the  hitch 
line  is  BKC  and  the  force  on  the  plow  bottom  is  sufficient 
to  draw  line  BKC  into  BGC,  more  power  will  be  re- 
quired to  pull  the  plow  because  the  front  wheel  will  have 
to  sustain  the  brunt  of  the  downward  pressure.  This 
naturally  will  cause  the  plow  to  run  on  its  point,  mak- 
ing an  uneven  furrow  bottom  and  interfering  very 
materially  with  the  pulverizing  of  the  ground  by  the 
mouldboard.  This  is  apt  to  throw  the  ground  over 
into  clods,  breaking  them  rather  than  pulverizing. 


174  THE  OLIVER  PLOW  BOOK 

If  the  plow  has  no  front  wheel,  it  is  equally  obvious  that 
the  bottom  will  go  deeper  in  order  to  straighten  the 
draft  line. 

If  a  wheel  plow  is  working  in  ground  that  is  hard  to 
plow  this  trouble  may  not  be  noticed,  but  the  instant  it 
strikes  easy  ground  the  trouble  will  become  plain  im- 
mediately. 

Another  way  for  the  operator  to  determine  whether 
or  not  this  point  of  draft  is  correct  is  to  raise  the  front 
furrow  wheel  and  also  the  landside  wheel  if  they  are 
both  well  to  the  front  of  the  plow.  The  plow  will  im- 
mediately begin  to  penetrate  deeper  and  deeper  if  the 
line  of  draft  is  not  straight  at  the  depth  desired  to  plow. 

If  the  plow  is  a  gang,  this  condition  will  cause  the 
front  bottom  to  penetrate  deeper  than  the  rear  bottoms. 
This  naturally  then  requires  lowering  the  hitch  at  K  to 
the  point  G  on  the  vertical  clevis. 

Side  draft  would  not  take  place  if  the  line  of  draft 
could  be  operated  parallel  to  the  furrow  wall.  The 
principle  back  of  adjusting  the  side  pull  is  identically  the 
same  as  that  of  adjusting  the  vertical  pull  with  the 
exception  that  it  operates  in  a  horizontal  plane.  If  this 
be  true,  the  question  of  why  cannot  this  line  of  draft  be 
operated  at  an  angle  as  successfully  as  the  vertical  draft 
at  once  arises.  The  answer  lies  in  the  construction  of 
the  bottom.  The  suck  and  wing  of  the  share  are  made 
to  permit  this  vertical  angle  pull,  while  it  is  impossible 
to  construct  a  device  that  will  turn  all  the  earth  to  one 
side  and  have  enough  resistance  to  keep  the  plow  oper- 
ating parallel  to  the  furrow  wall,  particularly  when 
the  side  pull  has  a  tendency  to  draw  the  rear  of  the 
landside  away  from  the  furrow  wall. 


THE  TRACTOR  PLOW  HITCH  175 


The  last  four  furrows  were  turned  with  the  plow  out  of  adjustment. 
Notice  the  ground  is  broken  and  pushed  to  one  side.  Compare  this  with 
the  rest  of  the  plowed  field  with  the  plow  in  adjustment.  This  picture 
furnishes  the  best  of  evidence  that  a  plow  should  be  in  the  correct  line  of 
draft  if  the  operator  desires  to  do  good  wor^. 


This  fact  brings  up  an  interesting  study  of  side  draft, 
because  the  results  of  such  adjustments  seem  to  be  con- 
trary to  what  one  would  expect.  The  reason  for  this 
unexpected  result  lies  in  the  fact  that  the  draft  bar 
attachment  from  a  tractor  to  the  plow  is  rigid  on  the 
plow  and  hinges  to  the  tractor.  Every  man  who  has 
operated  a  horse  plow  knows  that  to  make  a  right-hand 
plow  take  less  land  the  horizontal  hitch  is  moved  to  the 
left  of  the  center  line  of  draft,  and  if  he  desires  to  take 
more  land  he  moves  it  to  the  right  of  the  center  of  draft. 
He  also  knows  that  the  pivot  point  is  on  the  clevis  of  the 
plow  and  not  on  the  shoulders  of  the  horses  which  repre- 
sent the  center  of  power  the  same  as  the  hitch  on  the 
tractor,  hence  there  is  an  entire  reversal  of  the  order  of 
hitch.  One  cannot  expect  to  get  the  same  results 
because  there  is  a  vast  difference  in  the  application  of 


176  THE  OLIVER  PLOW  BOOK 

power;    although     the    law    that    the    draft    line    will 
straighten  itself  is  just  as  true. 

A  farmer  can  either  separate  his  horses  or  bring 
them  closer  together  to  approach  more  nearly  the 
straight  line  of  draft.  But  the  man  who  operates  a 
tractor  has  not  this  advantage.  In  order  to  approach 
this  line  of  draft,  he  must  either  run  his  tractor  in  the 
furrow  close  to  the  furrow  wall,  or  else  permit  of  side 
draft  when  plowing  is  difficult. 

Everyone  knows  that  it  requires  a  certain  amount  of 
effort  to  produce  a  given  result.  Figuring  energy  and  result 
as  weight,  we  can  readily  see  that  it  will  require  a  given 
weight  in  energy  to  produce  a  given  weight  in  result. 
Carrying  this  illustration  a  step  farther  we  know  that 
it  requires  one  hundred  pounds  weight  to  balance  one 
hundred  pounds  on  a  fulcrum  between  the  weights  an 
equal  distance  from  each.  Naturally  then,  if  the  greater 
weight  is  the  tractor  the  result  will  show  on  the  plow, 
but  if  the  greater  weight  is  the  plow,  the  result  will  show 
on  the  tractor;  and  where  the  weight  is  more  equally 
divided  the  result  shows  on  both. 

Since  the  pressure  against  the  mouldboard  varies  very 
greatly  in  a  given  field,  it  should  be  apparent  that  when 
the  tractor  begins  to  swerve  to  one  side  the  plow  is  in  a 
hard  condition  of  ground  and  naturally  is  exerting  itself 
to  straighten  the  draft  line  by  pulling  the  rear  end  of 
the  tractor  around  towards  a  point  in  the  center  draft 
line.  On  the  other  hand,  if  the  tractor  is  running 
parallel  to  the  plow  wall  and  the  plow  is  swerved  to  one 
side  it  is  plainly  evident  that  the  plowing  conditions  are 
light.  But  in  both  instances  the  operator  should  know 
that  he  is  not  approaching  the  draft  line,  and  that  the 
plow  and  tractor  are  doing  their  utmost  to  observe  this 


THE  TRACTOR  PLOW  HITCH  177 

law.  The  damage  that  is  done  to  both  the  plow  and 
tractor  cannot  be  estimated,  but  it  should  be  plainly 
evident  that  when  the  tractor  is  operating  at  its  max- 
imum capacity  and  the  rear  wheels  are  sliding  toward 
the  furrow  wall  and  the  front  wheels  pointing  to  the 
opposite  direction  on  account  of  the  operator  trying  to 
keep  the  plow  cutting  full  width,  there  must  be 
immense  tortional  stress  on  the  tractor  and  tremendous 
end  thrust  on  both  the  front  and  rear  axles  that  cause 
the  tractor  to  work  harder  than  when  the  tractor  is 
pulling  in  a  straight  line  of  draft.  As  a  matter  of  fact, 
experiments  have  been  made  which  show  an  increase  of 
power  required  from  15  to  25  per  cent,  to  say  nothing  of 
the  damage  done  to  the  plow  when  the  tractor  produces 
enough  power  to  spring  the  plow  out  of  shape. 

Fig.  6  illustrates  for  all  practical  purposes  a  perfect 
line  of  draft  through  the  center  of  the  plow  and  the 
center  of  power  on  the  tractor.  The  slight  distance  the 
tractor  is  off  center  will  not  affect  the  working  of  the 
plow.  When  the  plow  and  tractor  are  adjusted  to  this 
position  the  energy  of  the  tractor  is  directed  towards 
pulling  the  plow  straight  ahead.  There  is  no  side  force 
of  any  kind  to  be  overcome  in  the  operation  of  the  plow. 
Naturally,  the  minimum  power  will  be  required  to  pull 
the  plow.  The  plow  will  do  a  perfect  job.  Neither 
plow  nor  tractor  will  be  subjected  to  side  stress  which 
causes  unnecessary  wear,  and  oftentimes  sudden  break- 
age. 

When  it  is  necessary  to  hitch  to  one  side  the  tractor 
has  to  exert  power  enough  to  overcome  the  forces  which 
operate  against  this  line  when  it  deviates  from  the  center 
line  of  draft.  This  can  easily  be  seen  by  Fig.  7.  C  is 
the  center  of  weight  of  the  plow.  A  is  the  center  of 


178  THE  OLIVER  PLOW  BOOK 

power.  AC  then  represents  the  line  of  draft  which  is 
angular  to  EC,  the  force  which  should  act  to  pull  the 
plow  forward  in  the  perfect  line  of  draft,  if  the  operator 
desires  to  plow  properly. 

According  to  the  laws  of  physics,  AB  and  AE  consti- 
tute a  parallelogram  of  force,  hence  the  magnitude  of 
the  forces  AB  and  AE  is  proportional  to  their  length. 
In  this  diagram  the  proportion  is  14  to  4. 

Assuming  it  requires  540  pounds  to  operate  the  plow, 
this  means  then  that  420  pounds  are  required  to  pull 
the  plow  straight  ahead  and  120  pounds  to  overcome 
the  side  draft.  It  is  perfectly  plain  then  that  the  tractor 
which  is  hitched  to  one  side  of  the  center  line  of  draft  in 
this  case  is  required  to  withstand  a  tortional  stress  of  120 
pounds.  It  is  also  apparent  that  as  the  line  BC  is 
placed  closer  to  EA  the  proportion  of  forces  becomes  more 
evenly  divided. 

For  example,  if  the  hitch  between  the  tractor  and 
plow  were  shortened  so  that  ABCE  would  form  a  square, 
then  force  AE  would  be  equal  to  force  AB;  that  is,  the 
side  draft  would  be  increased  to  one  half  of  540  pounds. 
In  actual  practice  with  such  a  hitch  as  this  it  would 
require  more  than  540  pounds  to  pull  the  plow,  because 
the  tractor  would  be  operating  at  a  tremendous  dis- 
advantage on  account  of  the  additional  force  tending  to 
pull  the  rear  wheels  of  the  tractor  toward  the  line  of 
draft  (which  as  has  been  explained  previously  in  this 
chapter  will  always  straighten  itself  regardless  of  what 
forces  may  be  acting  against  it).  Hence,  it  is  evident 
that  the  hitch  on  the  tractor  must  be  in  a  straight  line 
from  the  center  of  weight  to  the  center  of  hitch  on  the 
tractor  if  the  minimum  of  power  is  required  to  pull  the 
plow. 


THE  TRACTOR  PLOW  HITCH 


179 


180  THE  OLIVER  PLOW  BOOK 

The  question  at  once  arises  as  to  why  the  plow  will 
not  swerve  around  so  that  the  line  AFC  takes  the  posi- 
tion AC  as  one  would  naturally  expect  it  to  do  if  the 
draft  line  is  to  straighten.  The  reason  for  this  lies  in 
the  draft  rod  brace  GH  which  is  solidly  fastened  to  the 
draft  bar  of  the  plow  and  the  frame  in  front  making  a 
rigid  connection  on  the  plow,  thus  bringing  into  play 
another  force  which  places  the  swivel  point  of  hitch  on 
the  tractor  instead  of  on  the  plow.  Naturally  when  the 
tractor  wheels  begin  to  move  towards  the  furrow  wall 
the  front  of  the  plow  must  move  in  the  same  direction. 

Both  the  rear  of  the  tractor  and  the  front  of  the  plow 
would  continue  to  move  in  this  direction  until  the 
opposing  forces  would  neutralize  each  other,  but  both 
the  plow  and  tractor  would  be  sadly  out  of  shape. 

Another  observation  from  such  a  condition  is  that  the 
draft  bar  I,  pulls  on  the  plow  and  the  draft  bar  brace, 
GH,  pushes,  thus  we  have  the  two  opposing  forces,  one 
pulling  ahead  as  it  should  and  the  other  pushing  back 
as  it  should  not. 

It  is  plainly  evident  that  undue  stress  is  placed  upon 
all  parts  of  the  plow  and  that  the  brace,  K,  is  utilized 
not  only  to  hold  the  plow  beams  the  proper  distance 
apart,  but  is  pushing  the  front  beam  and  the  parts  at- 
tached forward  to  offset  the  back  pressure  caused  by  the 
draft  bar  brace,  GH. 

It  is  further  apparent  from  Fig.  7,  that  the  farther 
ahead  the  tractor  is  hitched,  the  less  will  be  the  angle 
of  side  pull.  Then  it  follows  that  the  only  possible  way  to 
lessen  side  draft  when  conditions  will  not  warrant  putting 
the  tractor  into  the  true  line  of  draft  is  to  lengthen  the 
hitch  between  the  plow  and  the  tractor. 


THE  TRACTOR  PLOW  HITCH 


181 


182  THE  OLIVER  PLOW  BOOK 

This  discussion,  of  course,  assumes  that  the  plow  is  in 
perfect  working  condition.  Before  one  attempts  to 
make  adjustments  he  must  know  that  the  plow  will 
respond  or  his  efforts  will  be  futile.  Always  see  that 
the  shares  are  sharp,  with  proper  suck  and  wing,  all  the 
bottoms  are  scouring,  bolts  are  tight,  and  levers  working 
easily  before  attempting  to  make  final  hitch  adjustments. 


CHAPTER  XXI 


Adjusting  Horse  Plows 

A  WALK  ING  plow    is    the   simplest    form   of   plows. 
It   does   the  best  of  work  when   properly   hitched 
and   causes   the  operator    the   utmost   grief  if  the  draft 
line  between  the  horses  and  the  plow  is  incorrect. 

The  law  that  applies  to  the  draft  of  tractor  plows  is 
the  same  for  walking  plows,  but  the  application  is  radical- 
ly different  because  the  center  of  power  upon  horse  drawn 
plows  is  the  point  equal  in  height  to  the  average  point 
on  the  shoulders  where  the  tugs  are  fastened  to  the  hames 
and  midway  between  the  outside  horses.  The  draft  line 
between  the  center  of  draft  of  the  plow  and  this  point 
will  always  straighten.  The  center  of  draft  of  either 
a  walking  or  wheel  plow  is  exactly  the  same  as 
that  on  the  tractor  plow  discussed  in  the  third  paragraph 
in  the  chapter  "The  Tractor  Plow  Hitch." 

Because  this  draft  line  straightens,  the  depth  adjust- 
ments can  be  made  with  the  clevis  on  the  front  beam. 
Whenever  it  is  desired  to  cut  deeper  the  clevis  is  raised 
and  when  it  is  desired  to  plow  shallow  the  clevis  is 
always  lowered.  If  it  is  desired  on  a  right-hand  plow  to 
take  more  land  the  clevis  is  placed  to  the  right,  and  to 
the  left  to  take  less  land.  Of  course,  these  two  adjust- 
ments are  opposite  if  a  left-hand  plow  is  being  used. 

All  these  adjustments  are  made  to  keep  that  draft 
line  straight  at  the  depth  and  width  desired  to  plow. 


184  THE  OLIVER  PLOW  BOOK 

The  walking  plow  is  a  very  good  example  of  the  fact 
that  an  implement  does  not  require  a  pole  to  make  neck- 
weight. 

The  reason  why  sore  shoulders,  back,  and  hips  are 
prevalent  when  using  a  plow  with  or  without  a  pole  is 
because  the  traces  are  not  in  a  straight  line  from  the 
point  where  the  tugs  fasten  to  the  hames  on  the  shoulders 
through  to  the  center  of  draft  on  the  plow.  When  a 
horse  has  a  sore  neck  on  top  one  raises  the  tugs  at  the 
back  band.  This  is  evidence  enough  that  plowmen 
practice  this  principle  whether  they  know  it  or  not. 
The  further  fact  that  raising  a  tug  at  the  back  band 
often  makes  the  back  sore  is  positive  proof  that  we  are 
playing  around  the  straight  line  of  draft.  How  much 
better  it  would  be  after  the  plow  has  been  adjusted  to 
the  depth  one  desires  to  plow  to  see  that  the  hip  straps 
are  loose  and  that  there  is  no  downward  pull  on  the 
back  band,  no  upward  pull  on  the  belly  band,  no  chok- 
ing at  the  collar  and  no  bearing  down  on  top  the  neck. 

It  is  necessary  in  walking  plows  more  than  wheel 
plows  to  have  the  shares  absolutely  correct  before  any 
kind  of  adjustments  can  be  made.  Where  the  weight 
of  the  bottoms  is  carried  on  wheels,  the  work  of 
an  incorrectly  shaped  share  does  not  show  up  in  a  wheel 
plow  so  quickly  as  in  a  walking  plow.  For  this  reason 
if  the  operator  makes  all  the  adjustments  in  the  clevis 
that  can  be  made  and  the  plow  does  not  respond  to  the 
adjustments  it  is  plainly  evident  that  something  is  wrong 
with  the  share  or  some  part  of  the  plow  is  sprung  out  of 
shape.  It  is  reasonable  to  assume  that  by  far  the 
greatest  number  of  times  this  trouble  will  be  in  the  share. 
It  is  necessary  to  have  a  thorough  understanding  of  the 
setting  of  a  share  on  a  walking  plow  before  one  knows 


ADJUSTING  HORSE  PLOWS 


185 


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o  2  h 


a  «. 


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« 


186 


THE  OLIVER  PLOW  BOOK 


When  hitching  two  horses  to  a  sulky  plow  it  is  better  to  spread  them 
apart.  It  gives  the  advantage  of  having  fresh  air  circulating  around 
them  so  that  they  can  work  to  good  advantage  as  well  as  to  give  the  plow 
the  advantage  of  wording  in  the  true  line  of  draft.  A  thorough  under- 
standing of  the  draft  line  of  plows  will  save  a  great  deal  of  plowing 
trouble  which  is  unnecessary. 


whether  he  can  adjust  the  plow  as  he  desires  it  to  run. 
The  setting  of  the  share  is  discussed  in  Chapter  XV. 

When  two  horses  are  hitched  abreast  the  effect  is 
equivalent  to  hitching  two  forces,  one  on  each  side  of 
this  theoretical  center  line  of  draft.  That  is,  an  equal 
force  is  operating  on  each  side  of  the  center  of  weight  of 
the  plow.  These  horses  must  be  hitched  so  that  the 
leverage  is  the  same  for  both,  otherwise  one  of  the  horses 
will  be  doing  the  greater  amount  of  work.  The  closer 
one  adheres  to  this  theory  the  more  necessary  it  becomes 
to  regulate  the  width  of  singletrees  and  doubletrees  in 
accordance  with  the  size  of  the  teams. 


ADJUSTING  HORSE  PLOWS  187 


Every  few  years  plow  manufacturers  change  the 
angle  of  the  beam  in  relation  to  the  furrow  simply 
because  of  the  lack  of  knowledge  of  this  one  funda- 
mental part  in  hitching  to  walking  plows. 

If  a  walking  plow  cuts  14"  the  point  where  the  double- 
tree is  attached  to  the  plow  must  be  immediately  in 
front  of  the  landside,  which  is  21"  to  the  center  of  the 
previous  furrow.  This  would  make  a  doubletree  with 
the  two  outside  holes  42"  apart. 

To  pull  the  plow  straight  forward  the  efforts  of  the 
two  horses  combined  must  make  a  straight  line  parallel 
with  the  furrow  wall  the  width  the  plow  bottom  is 
cutting.  If  the  clevis  pin  is  too  far  to  the  right  of  this 
imaginary  line  the  plow  bottom  of  a  right-hand  plow  will 
immediately  begin  to  move  to  the  left  until  this  line  is 
straight.  This  is  the  reason  why  the  plow  takes  more 
land. 

Obviously  if  the  clevis  pin  is  hitched  too  far  to  the 
left  of  this  center  the  plow  will  take  less  land. 


When  a  walking  plow  is  properly  adjusted  it  can  be  operated  without 
the  operator  holding  to  the  handles.  The  test  of  a  man's  ability  to 
adjust  a  walking  plow  and  sharpen  the  share  is  to  make  that  plow 
operate  correctly  without  holding  the  handles. 


188  THE:OLIVER  PLOW  BOOK 

If  the  horses  are  hitched  tandem  a  somewhat  different 
result  takes  place.  That  is,  the  center  of  power  is  an 
imaginary  point  half-way  between  the  tug  staples  on  the 
hames  of  the  front  team  and  the  rear  team.  This 
requires  a  different  adjustment  on  the  clevis  of  the  plow 
if  the  same  depth  of  plowing  is  desired.  When  three 
horses  are  hitched  abreast  it  is  obvious,  on  account  of  the 
size  of  the  horses  and  the  narrow  furrow  being  turned, 
that  the  center  of  hitch  cannot  apply  to  the  center  of 
draft  of  the  plow.  It  must  be  moved  to  the  left  of  the 
clevis  in  order  to  give  the  horses  an  opportunity  to  work. 


CHAPTER  XXII 
Middle  Breakers 

OTRANGE  as  it  may  seem,  the  middle  breaker  is 
^  extremely  useful  for  very  wet  and  very  dry  ground. 
In  wet  ground  the  ridges  made  by  the  middle  breaker 
dry  out,  giving  the  air  an  opportunity  to  mingle  with 
the  moisture  in  the  ground  in  the  right  proportion  for 
plant  food  development.  Oftentimes  the  water  level  in 
the  ground  is  close  enough  to  the  surface  to  keep  a  seed 
bed  unduly  wet.  These  ridges  give  the  air  and  heat  from 
the  sun  a  chance  to  dry  out  the  ground  rapidly  enough 
to  develop  plant  food  for  the  growing  plants. 

The  lister  is  used  most  extensively  in  those  regions 
where  the  soil  is  light  and  sandy  and  the  evaporation  of 
moisture  is  excessive,  and  in  those  parts  of  the  country 
where  the  plowing  season  is  short. 

Listing  prevents  the  soil  from  blowing  and  enables  the 
crop  to  withstand  the  drought  of  the  semi-arid  climates. 
The  roots  work  deeper  into  the  soil,  the  surface  of  which 
is  exceedingly  warm.  This  places  them  in  contact  with 
more  moisture. 

Larger  acreages  can  be  handled  when  put  in  with  a 
lister  because  of  the  elimination  of  a  great  part  of  the 
labor  of  seed  bed  preparation.  The  lister  prepares  the 
ground  at  one  operation,  taking  the  place  of  plowing, 
disking,  harrowing,  and  packing.  This  is  a  great  incen- 
tive to  the  use  of  the  lister. 

The  lister  is  useful  in  a  climate  which  is  exceedingly 
wet  early  in  the  spring  and  dry  during  the  growing 
season.  The  use  of  the  lister  eliminates  much  early 
spring  plowing,  but  permits  the  farmer  to  get  onto  the 
field  and  plant  a  considerable  acreage  without  any  pre- 
vious soil  preparation. 


190  THE  OLIVER  PLOW  BOOK 

Farmers  in  those  localities  where  there  is  deficiency  in 
moisture  are  forced  to  farm  more  acres  to  grow  the  same 
amount  of  crop.  In  other  words,  they  must  secure  their 
rainfall  by  spreading  out  since  they  cannot  depend  upon 
a  great  depth  of  precipitation.  Here  listing  as  a  labor 
saver  is  a  very  material  consideration. 

Listing  is  practiced  in  two  ways.  In  some  sections  it  is 
the  sole  method  for  putting  in  corn  and  in  other  regions 
it  supplements  checking  and  drilling.  The  farmer  does 
what  early  spring  plowing  he  finds  to  do  since  fall  plow- 
ing for  corn  is  not  generally  followed  in  those  sections. 
When  the  rainfall  is  excessive  in  the  planting  season  it 
often  happens  that  only  a  small  part  of  the  proposed 
acreage  of  corn  has  been  prepared  for  planting.  In  such 
cases  the  general  practice  is  to  list  the  wheat  stubble  and 
corn  land  with  a  two-row  lister  completing  planting  in  a 
very  short  time.  While  listing  is  not  adapted  to  a  wet 
growing  season,  it  is  very  useful  when  the  early  spring  is 
exceedingly  wet  and  the  summer  dry. 

In  communities  where  listing  is  practiced  there  is 
always  more  or  less  discussion  in  regard  to  the  effect 
listing  has  upon  the  seed  bed.  The  objection  is  often 
heard  that  listing  leaves  hard  ridges  throughout  the  field 
which  subsequently  become  baked  and  leave  the  soil  in 
bad  texture.  This  is  true  when  listing  on  clay  and  clay 
loam  soils.  On  light,  sandy  soils  this  objection  is  not  a 
serious  one. 

A  twenty  years'  observation  of  fields  which  have  been 
listed  every  other  year  shows  that  those  soils  which  are 
adapted  to  the  practice  are  exceedingly  mellow  and  no 
bad  effects  have  been  found  in  the  ridging  of  the  soil. 
Here  the  practice  has  been  to  list  at  right  angles  to  the 
last  listing. 

Another  objection  to  listing  often  raised  is  that  if  the 
season  is  wet  the  soil  in  the  furrow  will  bake  and  crust 
over  so  that  the  corn  cannot  break  through.  Here  the 


II 


3* 


192  THE  OLIVER  PLOW  BOOK 

objection  is  unfounded  where  listing  has  been  practiced 
on  the  kind  of  soil  for  which  it  is  intended.  Baking  so 
that  the  corn  cannot  break  through  has  not  been  observed 
in  the  light  sandy  soils.  There  have  been  some  very  sad 
experiences  with  listing  on  heavy  packing  soil. 

When  the  field  has  been  listed  and  properly  tended  so 
that  the  last  cultivation  levels  the  ridges  it  has  prac- 
tically the  same  kind  of  surface  as  checked  corn.  There- 
fore the  customary  rotation  of  small  grain  and  corn  can 
be  practiced  to  advantage.  The  prevalent  method  of 
putting  in  the  small  grain  crop  is  to  disk  the  field  which 
was  previously  in  corn  in  the  early  spring.  Where  the 
cultivating  has  been  properly  done  and  the  ridges 
entirely  leveled  no  difficulty  is  encountered  in  seeding 
the  spring  grain  in  the  cornstalk  field. 

To  be  brief,  the  advantages  of  listing  are  as  follows: 

1 .  The  prevention  from  blowing  of  light  soils  due  to  the 
ridges  of  the  field. 

2.  The  saving  of  moisture  and  the  use  of  more  sub- 
soil moisture  by  putting  the  roots  deeper  into  the  ground. 

3.  The  saving  of  labor  in  the  early  spring. 

4.  Permitting  a  larger  acreage  than  would  otherwise 
be  possible  since  it  supplements  planting  in  ridges  where 
moisture  conditions  are  difficult. 

The  middle  breaker  or  "lister"  is  a  combination  of  a 
right-hand  and  a  left-hand  plow  bottom  without  the 
landside,  the  object  being  to  throw  the  dirt  to  turn  a 
furrow  slice  in  both  directions.  This  construction  per- 
mits one  mouldboard  to  act  as  a  landside  to  the  other, 
however,  in  the  uses  to  which  the  middle  breaker  is  put 
there  is  often  greater  pressure  against  one  of  the  mould- 
boards  than  the  other.  This  would  naturally  cause  the 
entire  bottom  to  swerve  towards  the  side  of  least  resist- 
ance until  the  pressure  against  each  mouldboard  would 
be  equalized.  To  offset  this  a  steel  rudder  is  placed 
midway  between  the  two  bottoms  to  penetrate  into  the 
ground  to  keep  the  bottom  operating  in  a  true  line  of 
draft  when  these  unequal  conditions  are  encountered. 


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CHAPTER  XXI II 


Disk  Plows 

THE  disk  plow  has  altogether  a  different  effect  upon 
the  ground  than  the  mouldboard  plow.  The  mould- 
board  plow  turns  the  earth  with  a  crunching,  pinching, 
pulverizing  motion  while  the  disk  plow  turns  the  earth 
with  a  rolling  motion.  Naturally  the  earth  turned  with 
a  disk  plow  will  have  more  clods  and  larger  ones  than 
when  turned  with  a  mouldboard  plow.  The  scrapers 
aid  the  disks  very  materially  in  covering  trash  and  reduc- 
ing the  size  of  the  clods. 

Oftentimes  ground  becomes  too  dry  to  be  successfully 
turned  with  a  mouldboard  plow.  Primarily  the  disk 
plow  was  designed  for  turning  soils  in  this  dry,  hard 
condition.  It  becomes  apparent  at  once  that  such  a 
plow  can  be  used  to  good  advantage  in  localities  where 
fall  sown  crops  are  to  be  planted  and  the  summer  rain- 
fall is  apt  to  be  scant.  The  rolling  motion  of  the  disk 
turning  the  furrow  leaves  the  ground  in  a  looser  condi- 
tion than  a  mouldboard  plow,  hence  it  better  absorbs 
the  rainfall  that  may  come  before  the  time  of  planting. 
For  this  reason  there  are  plenty  of  farms  on  which  both 
disk  and  mouldboard  plows  can  be  profitably  operated 
in  the  season  better  adapted  to  their  use. 

The  disk  plows  are  in  common  use  in  gumbo,  hardpan 
and  black  waxy  soils  where  mouldboard  plows  will  not 
scour. 


196  THE  OLIVER  PLOW  BOOK 

A  disk  plow  can  be  set  to  work  in  any  type  of  soil  but 
wherever  a  mouldboard  plow  operates  it  is  better  to  use 
a  mouldboard  plow  because  it  does  a  superior  quality  of 
pulverizing.  The  disk  plow  will  not  turn  so  good  a 
furrow  in  a  light  sandy  soil  as  a  mouldboard  plow  will, 
neither  does  it  work  so  well  as  a  mouldboard  plow  in 
plowing  weedy  stubblefields  or  grasslands  where  mould- 
board  plows  scour. 

Dry  plowing  has  been  interesting  farmers  a  great  deal. 
The  conclusion  reached  from  the  plowing  of  dry  ground 
in  the  hot  summer  is  that  the  evaporation  of  moisture 
from  the  sub-soil  is  greatly  lessened  and  the  land  derives 
much  greater  benefit  from  driving  rains.  That  is,  more 
of  the  rainfall  sinks  into  the  ground.  The  weeds  also 
get  an  earlier  start,  providing  there  is  sufficient  moisture 
in  the  ground,  thus  giving  a  better  opportunity  to  kill 
them  with  a  disk  before  sowing  time.  Earlier  sow- 
ing also  results.  This  has  proved  to  be  of  special 
benefit  in  those  localities  where  it  is  necessary  for 
the  crop  to  have  a  good  start  before  the  winter's 
freezing  sets  in.  It  has  been  proven  many  times  that 
dry  plowing  immediately  following  the  harvest  is  the 
means  whereby  a  crop  is  made  possible  where  other- 
wise none  could  be  grown.  This  dry  condition  nearly 
always  takes  place  on  soil  that  cannot  be  plowed  while 
hard  and  dry  with  a  mouldboard  plow. 

The  disk  plow  will  handle  very  gravelly  soil  where  a 
mouldboard  plow  cannot  work.  The  principal  reason 
for  this  is  that  the  disk  plow  does  not  cut  so  wide  a 
furrow  as  the  mouldboard.  The  gravel  in  these  narrow 
furrows  is  separated  with  the  rolling  motion  of  the  disk 
much  more  effectively  than  can  be  done  with  the  crunch- 
ing, pulverizing  action  of  the  mouldboard.  Another 


DISK  PLOWS 


197 


Tractor  disk  plow  showing  the  way  the  disk  plow  turns  the  soil  and 
also  that  a  straight  furrow  can  be  turned  with  one  of  these  implements. 


advantage  of  the  disk  plow  in  this  type  of  plowing  is 
that  when  it  is  desired  to  do  deep  plowing  better  results 
can  be  secured  by  having  each  disk  cut  a  narrow  slice. 


198  THE  OLIVER  PLOW  BOOK 

Three  disks  equally  spaced  to  cut  24"  wide  will  naturally 
do  better  work  than  two  disks  spaced  to  cut  24"  wide. 

Many  insect  pests  of  which  the  grasshopper  is  the 
most  common  can  be  successfully  fought  with  the  disk 
plow  because  of  its  qualities  for  turning  hard  ground. 
It  is  a  well  known  fact  that  grasshoppers  lay  their  eggs 
in  nothing  but  hard  ground.  Infested  fields  will  produce 
grasshoppers  the  next  year  unless  something  is  done  to 
prevent  such  a  calamity.  Whether  or  not  a  farmer  expects 
to  plow  the  infested  field  in  the  fall  he  can  very  greatly 
diminish  the  crop  of  grasshoppers  the  following  year  if 
he  will  plow  the  preceding  fall.  There  are  plenty  of  sec- 
tions in  the  United  States  where  farmers  could  use  the 
disk  plow  earlier  in  the  season  for  no  other  purpose  than 
this  and  save  themselves  several  times  the  price  of  the 
plow  in  the  next  crop. 

As  to  the  draft  required  to  pull  a  disk  plow  there  is  no 
evidence  to  show  that  it  pulls  any  lighter  than  a  mould- 
board  plow  which  turns  over  the  same  volume  of  earth. 
Many  people  deceive  themselves  into  thinking  that  a 
disk  plow  pulls  lighter.  The  reason  for  this  is  probably 
because  the  disk  plow  does  not  cut  quite  so  wide  a  furrow 
as  the  mouldboard  plow.  This  characteristic  gives  the 
disk  plow  an  advantage  over  the  mouldboard  plow  in 
that  whether  one  cuts  a  wide  or  narrow  furrow  with  the 
disk  it  always  does  an  equal  quality  of  work,  whereas  a 
mouldboard  that  cuts  either  a  wider  or  narrower  furrow 
than  the  width  intended  decreases  the  quality  of  plow- 
ing. A  too  wide  furrow  leaves  an  unplowed  strip  and  in 
a  too  narrow  furrow  the  ground  is  not  properly  pulver- 
ized. 

The  disks  are  sharp  and  placed  on  the  frame  so  that 
they  present  a  cutting  edge  to  the  soil  very  similar  to 


200  THE  OLIVER  PLOW  BOOK 

that  of  a  knife  blade  when  one  whittles  a  stick.  The 
disk  has  the  advantage  over  the  knife  blade  in  that  the 
edge  of  the  disk  cutting  the  soil  is  constantly  changing. 
For  this  reason  the  edge  of  a  disk  will  retain  its  sharp- 
ness a  great  deal  longer  than  the  edge  of  a  share.  This 
fact  very  probably  has  a  great  deal  to  do  with  the 
superiority  of  this  type  of  plow  over  the  mouldboard 
plow  in  exceedingly  hard  ground. 

The  principle  of  the  draft  of  a  disk  plow  is  entirely 
different  from  that  of  a  mouldboard  plow.  The  shape 
of  the  share  and  mouldboard  of  the  mouldboard  plow 
cause  the  bottom  to  be  pulled  into  the  ground.  On  the 
other  hand  a  disk  plow  must  be  forced  into  the  ground 
by  weight  and  draft  combined. 

In  operating  a  disk  plow  the  hitch  in  front  should 
always  be  adjusted  so  as  to  keep  the  front  of  the  plow  in 
the  ground  and  sufficient  weight  added  to  the  rear  to 
keep  it  in  the  ground  at  the  desired  depth. 


Notice  the  curved  furrow  wall  and  bottom  and  the  way  the  earth  is 
delivered  as  a  turned  furrow.  It  is  entirely  different  from  that  of  a 
mouldboard  plow. 


14  DAY  USE 

RETURN  TO  DESK  FROM  WHICH  BORROWED 
LOAN  DEPT. 

This  book  is  due  on  the  last  date  stamped  below,  or 

on  the  date  to  which  renewed. 
Renewed  books  are  subject  to  immediate  recall. 


Slan'MFC 

JREC'D  LD 

FEB  2     1959 

LD  21A-50m-9  '58 
(6889slO)476B 


General  Library 

University  of  California 

Berkeley 


